Intimidated by LS wiring? Where I connected loose wires for my OBS Chevy Cheyenne Cammed 5.3 LS swap

[@bradmcdonald6220]

Awesome video, finally someone that knows how to explain something in detail and not just a bunch of random information.

[@charliebrown5528]

This video and commentary were PERFECT all around. I have a 1995 OBS an everything you explained worked to the T. All gauges are working and I am on the road in less than 15 days start to finish. I especially liked the TCC wire hook-up to the ABS. I was able to do everything with the information you provided. Great job and thank you

[@laurencevillegarage]

Thank you, glad to hear you got it running so quickly. Have fun! Mine puts a smile on my face every time I start her up!

[@zzombiekilla246XD]

Did u use the 1995 4l60e? I heard there's a way to do it but cant find anything about it online. Was thinking I might need a newer 4l60e because the 1995 4l60e was obd1 and I have a 2002 5.3 I'm putting in.

[@gerardolopez5875]

@@laurencevillegarage @@ amigo, on a 93 obs, swap, there’s a small module near master cylinder,, Has a purple wire on it, it cuts off when brake applyed,, Should i cutt it to hook tcc?? Or should i splice tcc wire into it????

[@laurencevillegarage]

@@gerardolopez5875 splice don’t cut.

[@gerardolopez5875]

@@laurencevillegarage @ thanks,,, nice truck,,,, Are building a 92???

[@marvelous_1372]

I'm a transmission builder. The switch on the side of the transmission is also known as a PRNDL switch you can either use a heat gun to soften the glue or you can hang an incandescent bulb in a drop light on the plug area for 20 to 30 minutes. To reinstall the plugs I use a cheap cigarette lighter to heat the glue on the plugs moving the flame around the glue until it starts to bubble. Install the plugs while the glue is hot and it will plug in with no issues.

[@laurencevillegarage]

Good to know, I'll try this next time. Thanks for sharing.

[@larryjohnson3033]

I've searched all over for this kind of video, thank you sir for taking your time to upload this, I very well so appreciate this information that you have put together for us

[@laurencevillegarage]

You're very welcome! Glad you found it helpful!

[@Triggerman2505]

...you sir are a gentleman and a scholar and a God's gift to GMT400 LS swap community. This just made my life so much easier. Pulling the motor out today on my 88 2500 2WD and putting in a 2006 L33 and this is just want I needed.

[@laurencevillegarage]

Thank you, I'm glad it was helpful. Good luck with your swap!

[@OldSoul85]

@@laurencevillegarage thank you for your videos. They are very informative. I’m researching right now. I’ve got an 89 k1500. One thing I can’t get a clear picture for, 1.) the original pcm/ecm behind the glove box, does it stay or go? 2.) I thought the LS harness has to connect to the obs harness behind the glove box? Any information is greatly appreciated.

[@laurencevillegarage]

@@OldSoul85 for the most part it goes. The LS harness doesn’t really connect to it as much as connecting a number of loose wires from your LS pcm. The only one needed to actually run the engine are red for constant power, pink for “key on” power and grey for your fuel pump. The remaining wires are for gauges and a/c. It all depends on which features your truck has and what you want to function. For example, your truck probably has a/c, but, you may choose to not have a/c or to use cruise or maybe (like my 91) you don’t have a tach gauge. To make your life easier, as you remove or disconnect your present wiring, label everything you take off and don’t cut anything you don’t absolutely have to laying everything to the side. In my case I taped everything to the windshield to get out of the way. This way when you start to connect all the LS stuff you can find it better. Once everything works that you want THEN you can thin out all the wires you find you do not need. At that point, if all wires have been pulled from the “old” pcm, then just remove it. I find it just make my life more complicated if I start cutting stuff off first. You might cut something you need for later and tracking it down is now more complicated. Keep it as easy as possible. I also recommend getting a GM factory electrical wiring manual for your year truck. I get mine off eBay. They are an excellent investment and extremely detailed. A great resource to help you when few others can. Chilton and Haynes manuals are not much help on wiring. Remember, you are creating something that the “average” mechanic will be clueless about. Keep notes and part numbers as you go, this will be a big help a year from now if something doesn’t work and you have to troubleshoot the issue. You are the only one who will know exactly how you put it together. That’s why I only remove what has to be. You don’t want to end up with a hack job.

[@OldSoul85]

@@laurencevillegarage thank you so much for responding. You cleared up alot of questions.

[@tomhayes6920]

Your video was amazing. It was just what I needed. Thank you very much. I was beginning to get a little overwhelmed

[@laurencevillegarage]

@@tomhayes6920 thank you!

[@tomhayes6920]

@@laurencevillegarage the grey wire under the fuel relay. Do you remember what one to hook it to?

[@sagispeedshop6427]

Gosh, the information in the video is spot on. Very good job explaining in good detail.

[@jaredrandall80]

Thank you so much for this video !!! The amount of information and specific details in this is absolutely priceless. Especially for me. I'm gathering all of the parts rite now and just got done rebuilding a 2004 6.0 and nv4500 5 speed manual to swap into my 1999 4 door 2500 4x4 and I have been worried sick about the wiring and how to make the ls harness work properly and have everything in the 99 truck work as it should and not be a complete nightmare, hackjob. Thank you so much for posting this video, this helps me more than you could even know and has me way less stressed and worried about doing this swap. Thank you so much for the information and help and that is a gorgeous truck and the swap looks amazing. Looks like it came that way out of the factory. Incredible work and priceless information !!!

[@laurencevillegarage]

Jared, thank you for the kind words! I’m glad you found the video helpful. Sounds like a great swap project, good luck!

[@hulkmadddhernandez6113]

Thanks bro exactly what I needed. Need more people like you thank you. Houston TX

[@staticobs2370]

After watching this my obs decided she finally wanted to run thanks man

[@aaronmartin2399]

Swapping a 95 z71 couldn't do it without your help thanks and God bless keep up the good work and video's

[@laurencevillegarage]

Thank you, and good luck with your Z71!

[@shawnmalicek1189]

Did you use your 95 4L60e trans in your swap? Thanks

[@aaronmartin2399]

@@shawnmalicek1189 no I used the 05 4l60e out of my donor truck

[@laurencevillegarage]

@@shawnmalicek1189 No, I used the 4l60e that was from the same donor vehicle as the engine.

[@shawnmalicek1189]

@@laurencevillegarage okay thanks

[@LNGHRNS06]

Excellent video. I wish there were videos and information like this way back when I did my swap. I'm basically to the point of having to re-wire the entire truck. Greetings from across the DFW metroplex. (I'm west of Fort Worth).

[@laurencevillegarage]

Thanks, its a work in progress. Got family over near Azle, small world!

[@lenorddelafuenteiii492]

Me and my dad are working on finishing up the wiring in my 98 ls swap. This was some very helpful information. Thank you 👍

[@laurencevillegarage]

Glad you found it helpful. Good luck with your project!

[@lenorddelafuenteiii492]

@@laurencevillegarage thank you. It was quite intimidating at first but once we started making sure everything was labeled and started tracing all the wires to where they go it was a little less intimidating lol. I now know where there is some great info when I need it. Again thank you sir. Great looking swap.

[@newmexicosaint]

Man this video is so informative!! I have saved this video to reference later! Thank you for taking the time to make and post this!!

[@laurencevillegarage]

You’re welcome, good luck with your project!

[@rcs_rc_az961]

Great video/ editorial! Thank you for taking the time to edit and put all of this together, theres a great wealth of knowledge from experience here.

[@laurencevillegarage]

Glad you enjoyed it!

[@kyleblume6530]

Perfect video THANK YOU sir. I’m doing my ls swap soon and to know what all of these wires do and where to go with them is so helpful!!!

[@laurencevillegarage]

kyle blume Thank you sir, good luck with your project.

[@kyleblume6530]

This is by far the most detailed gmt400 swap video for wiring!!!

[@StraightOuttaContent]

Greatest looking truck ever made

[@pennickspeedshop8846]

Good info. Good stuff to know as I will be LS Swapping my 1990 c1500 very soon.

[@vdub4201]

very helpful.. im in the middle of doing a 5.3 4l60e swap on a 89 c2500 that had a 4.3 and 5 speed manual.. just starting on the wiring.. ordered a stand alone engine and trans harness. this was very helpful, or will be when i wire it up for the original gauges.. yeah.. i broke, on purpose the neutral safety switch.. laying on my back on the floor after 30 minutes trying to get it off, just got mad and yanked on it and it snapped.. luckily it was cheap to replace..

[@laurencevillegarage]

I did the same thing! Special adhesive put on st factory to keep moisture out. I read I’d heated with a heat gun will soften it and it’ll come off easier. I was too impatient! Good luck!

[@tedtolentino4955]

vdub4201, sorry to go off topic with my questions, but I have an '88 c1500 with the 4.3L and the 5 speed manual trans. I see that your project vehicle is a c2500 3/4 ton pickup. Did you have any issues with the truck being underpowered as a 3/4 ton truck? I am contemplating doing an LS swap, but also beefing up my suspension with parts from a c2500 donor truck, including the heftier rear axle. My purpose is to have an all-around hauler around town, for the landscaping projects I am involved with, with an occasional longer highway trip as needed. I'll stick with the v6 (no issues at the moment) until I can find a good used LS to swap into it. To Lawrenceville Garage, thank you for sharing such a detailed video on your LS swap. This is what I sorely need to fill the gap in my knowledge of wiring, especially in doing for my first time an engine swap.

[@vdub4201]

@@tedtolentino4955 when i got the truck the previous owner stole all the stuff of the front of the engine, and it had been sitting for years so i had no interest in fixing that engine.. i paid 700 for a running 03 suburban, the parts to complete the 4,3 would cost mor than i paid for the whole suburban soo.. sold the 4.3 and 5 speed for half what i paid for the truck, then parted out the rest of the suburban for almost what i paid for it..

[@lordcyclone2011]

well... mine is an 09 colorado with a 5.3 LS gen 4.... but even so alot of work... and alot of surprises... these swaps simply take time... and patients.... alot of trial and error for your specific vehicle... and i have already watched alot of videos on these colorado LS swaps

[@lordcyclone2011]

the old engine was a 2.9 4 cylinder

[@lordcyclone2011]

still running into issues they didnt completely cover

[@laurencevillegarage]

You are right, a lot of trial and error! There is no specific recipe that works for each persons engine / body choice + options etc.

[@HEYBERT1984]

Thx for the vid really good info in there. Just did a ls3 swap on my 1970 impala best decision ever.

[@galenyoung8349]

I've got a 96 Blazer I thought about LT1 swapping. The AC compressor & oil pan & backwards flow cooling system & computer/flash & delete(s) issues were gonna be huge due to logistics & budget on my build. I was looking at around 300.00 to delete vats, egr & tune to get it "started." Then, after that, they sky is the limit with the time guy? In my case I'd be inclined to wanna start out with completely rebuilding my engine & replacing everything "in" & "on" the daym thing coz pulling/installing engines In either generation of S10 is a nagger head. They promote FOUL language & TONS of, hours & dead presidents. I've got a running driving LT1, Donor car. I also have a 2WD 92, S10, Tahoe, with a 2.8 running/driving in it. Excellent video, sir.

[@laurencevillegarage]

Just my .02 Galen, kudos for the running donor by the way… But, you are going to spend some $$ going that route with an LT1. It would be less $ and easier to swap an LS based engine AND it will produce more hp dollar for dollar spent. If it were me, I would find someone who wants to swap an LT1 and sell the donor and use that coin to buy a 00-03 Tahoe/suburban with a 5.3 (around here they run 750-1400 all day long). Pull everything you need, sell off the rest and may be able to recoup your cash. For Hp, there is a lot more support and fewer headaches involved. Thanks for watching! Good luck!

[@jevonmorris]

This is an awesome video. You addressed in detail the things that kinda get glossed over on other videos (mostly because they are for such a broad audience). Than you sir.

[@Ghostcycles]

This is proper and detailed info. Thanks to you this will complete my journey to my LS swapped 1996 c1500 💪🏾

[@laurencevillegarage]

Glad I could help

[@memoloco328]

Very very informative, just what i was looking to find, great job!!! Al tho im not doing an ls swap this helps with my microsquirt setup! Thanks

[@JoseContreras-mv5yz]

Damn swap looks clean and factory looking👌

[@Brykk]

Beautiful truck. Great job on the swap. Ill be using this to help me with my swap and ill be pointing people to your video as a reference.

[@laurencevillegarage]

Thank you, glad it was helpful!

[@MrFlintmica]

Doing a swap on my 92 k1500 this spring/summer. This def put my mind at ease. Not nearly as scary as i made it out to be lol.

[@laurencevillegarage]

Great to hear, good luck with your project. It really is not as scary as you might have thought. Get a GM electrical wiring manual (not a disc) a real manual. It is excellent source of information and is not that expensive. I get mine off of ebay...depends on year, but I have paid as little as $11 and as high as $30. It is worth every penny! You can always sell it in the future if you move on to different projects and don't need it anymore. Me, I keep them all....you never know when you might need it.

[@1badnissan09]

I gotta say that is one of the cleanest swaps iv seen. Awesome job👍🏻

[@laurencevillegarage]

Thank you very much! I am trying to plan out another project. I have my donor vehicle, a 2004 Tahoe. It may take awhile, but I hope to capture the complete build with more of a theme...like a "how to: muscle truck with a $5K budget".....something that would be more like the "low buck" builds the car magazines used to do years ago.

[@Wickedjc2119]

I seen the thumbnail of this truck. I had to stop in and say. Beautiful truck

[@laurencevillegarage]

Thank you, hope the video was helpful.

[@Wickedjc2119]

Didn't watch the video. Just seen the truck lol

[@jmc7991]

Great video but looked through all the comments & didn’t see how you got the pnp to work. Mine starts in any gear & reverse lights won’t work. Do you need the shift indicator working to make this happen? & for those of you with the 4x4 what I did to get the transmission to work was hooked up the hi & low vss wires from the new pcm to the hi & low wires for the vss coming from the DRAC (same color wires)& the green pin 50 wire to green speedo wire from the DRAC. Then i jumped my wires from the output vss on the trans to the transfer case vss & all good. Haven’t hooked up the 4wd yet but I believe hooking pin 16 from the new pcm to the low vss wire from the DRAC as well should do it.

[@laurencevillegarage]

My truck is 2wd and was a 4L60e and the Tahoe trans was the same. With that said, there is a shift module mounted on the driver side of the trans. It had 2 plugs: upper plug with ~7 wires and a lower one with 4. The lower connection (or 4 wires) is for the shift indicator lights on the dash. On my truck, I spliced the original 4 wires into the 4 on the plug that was on the Tahoe harness. This allowed all my dash lights for the PRNDL2L1 to illuminate and function correctly.

[@MrJacalhoun30]

That's a good looking truck u have there. Very clean. Used to have a step side GMC the same color.

[@laurencevillegarage]

Thank you! Don't see very many trucks of this era in this color. The paint is in pretty good shape, and it is the original paint!

[@ovaddiesanchez-martinez885]

Great info. I did a lq9 408 into my 96 4x4 Tahoe and did something very similar to your setup. I used the schematics to trace and remove all my old unnecessary wires. I then integrated the ls ecu to my old wiring for the dash info. One thing I did different is screw the obs temp sensor into the passenger head so I didn’t need to tap into any of the wiring. The passenger head send temp to dash and the driver head sends the temp the the ls ecu.

[@laurencevillegarage]

You are correct and I like that idea. That is what I plan to do on the '01 project I'm about to start. Thanks for sharing!

[@glo5959]

Thank you for this video very informative and just what I needed I’m very appreciative of your hard work and taking time to make us a video into detail happy to subscribe to your channel

[@laurencevillegarage]

Glad it was helpful!

[@Zelaznogsiul-63]

I have been thinking about doing an ls swap on my 1990 Sierra, but the wiring even with your great video is difficult, I will probably put a 350 when I replace the 305. Thank you for the video.

[@laurencevillegarage]

Either way you will enjoy the upgrade. I know the wiring is intimidating. But, after you do one, it really isn’t as bad as you might think. Just work it 1 wire at a time and you can do it. Either way you go, have fun with it, don’t let it stress you out!

[@Zelaznogsiul-63]

@@laurencevillegarage thank you for the quick reply, I subscribed to your channel, great info.

[@laurencevillegarage]

@@Zelaznogsiul-63 Thank you!

[@firelordvsgaming7258]

DUDE THANK YOU! I’m not doing the same exact swap but you just helped me so much

[@laurencevillegarage]

Glad I could help!

[@scottydoesntknow254]

ACDelco D1818A for a oil pressure sensor that will screw into the LS valley cover and read with the stock gauge.

[@laurencevillegarage]

Good to know, thank you.

[@thabigghomie_]

Love the video Start my swap now same truck 88 With a 2001 5.3 💪🏾💪🏾💪🏾💪🏾💪🏾very helpful Might hit you up on some more stuff with the truck when i started got my harness off ebay

[@tahoeboy5299]

What harness u go with

[@thabigghomie_]

Psi harness

[@laurencevillegarage]

I sent mine off to Chris at easyefisolutions.com, he modified the harness and tuned (initially) my pcm.

[@jaket.9193]

Excellent information. Thank you

[@dennisroberts2857]

Very nice video! I'm think of doing this swap. Lots of valuable information!

[@mikemittens6492]

Awesome job on your swap and awesome job on this video thankyou very much

[@josephroy4132]

Good video. It be nice to see what your saying but u did a good job explaining it

[@laurencevillegarage]

I would have liked to, but there was much trial and error. If I showed too much, it would have been boring, not showing enough folks wonder what was edited out. Next build, I will do a lot more detail and include more information. Thank you for the kind words and comments.

[@kyandrepaige209]

Great video and beautiful truck!! You did a great job and you explained everything very well!!

[@missingremote4388]

I have a 1995 Suburban. Looking at many engine swap videos... for useful information. However, I'm doing ( or currently paying a pro shop to R&R) a engine & transmission on my 08 lacrosse 3.8 V-6

[@laurencevillegarage]

Its a good idea to get as much information as possible before you jump in to the swap. The '95 Suburban should be very similar to my swap, so the information should be useful. Thanks for watching and good luck with your swap.

[@missingremote4388]

@@laurencevillegaragedriving my Suburban more this month.... Seems okay, but I have a car and a suburban... My car is the one that broke.

[@joedirt1712]

Thank you. Going to do the same build as you on a 95 Chevy 6v/ stick.

[@laurencevillegarage]

Good luck! Let me know how it goes.

[@daviddatdude6010]

THIS IS A BIG HELP! GODSPEED!!

[@laurencevillegarage]

Glad it was helpful!

[@brianbonner8069]

Hi. If you heat those 2 plugs on the shift indicator module with a heat gun they'll come right loose without damage. I only heated them about 10 seconds.

[@laurencevillegarage]

mine had so much glue on them, I don't think it would have helped. I'll give it a try next time, thanks.

[@ChrisfromGeorgia]

Beautiful Truck! Thank you for the detailed video.Btw, Laurenceville GA? Take care from new sub.

[@laurencevillegarage]

Thank you!, Not in GA, in Rockwall Tx

[@PreparedPatriotNC]

Subscribed and will follow. Great video!

[@laurencevillegarage]

Welcome aboard! Thanks for subbing!

[@jeremysmith2753]

For your alternator wiring. Now did you just piggyback your factory obs harness 1 wire in the plug in off of the wire in the same location on your LS harness? Hopefully that makes since i hope as im using a BP harness and the factory obs harness and im attemptingto do this for the gauge. I also noticed on my LS harness it has 2 wires in the plug in and my obs plug has 1 wire. Please let me know what you did and thank you for any information in advance and keep up the awesome work and for letting us see your very detailed work and thourough explanations!!!!!!!

[@laurencevillegarage]

Thanks Jeremy, I'm not certain how the BP harness is configured, but, the one wire coming off my alternator goes to red pin 15 brown wire. Not sure if this helps or not.

[@marksmith8720]

I would just like to say thanks for making such a good video. Helped me lots! I'm doing a Similar swap on my 95. I am also running the cruise module from my 2001 parts truck. When you wired it up did you cut the light blue wire from the old computer and wire it directly to the new computer to make it work? That's the only wire I can tell I should need. Just figured I'd ask because yours works. Thanks!

[@laurencevillegarage]

Thank you Mark, I'm glad you found the video helpful. As for the wire, no, I did not. I attached the 3 main wires from the 5.3 harness to make it run. You still need the '95 pcm to do other stuff. One by one I connected all the remaining wires in the modified Tahoe harness. The only wires I eliminated from the original '95 harness were those that were specific to the V6 that would not be needed. When all my lights, gauges and cruise were working, I thinned back the unused wires farther back in the '95 harness. I did not remove any pins from the '95 pcm or modify any '95 wiring inside the cab. Hope that helps.

[@JUANPEREZ-vp3mf]

very informative, thank you

[@NorthCoastT]

Great job on the truck and video.

[@laurencevillegarage]

Thank you, positive words are always appreciated. I am looking for a new project truck (already have the donor!), when I find the truck I want to use, I'll post up videos from the very beginning. Thanks again.

[@NorthCoastT]

@@laurencevillegarage you're welcome. I subscribed so i can catch the next video. I just started doing some upgrades on my 1992 one ton truck. Nothing like what you've done but upgrades none the less. I already have the 5.7L and just opened up the exhaust yesterday. Working on the before and after video now.

[@LJimenez0185]

Thanks for the info, can you make another video with parts needed and tips to make an LS Swap on this 88-98 truck? I know it might be different depending on the year but at least to help us, thanks nice video!

[@laurencevillegarage]

Thank you for the kind words. I plan to do just that on my next project. When doing almost all the work myself plus recording, it takes more time and I sometimes tend to get impatient and want to see results faster. I did record a lot on this truck, but I overlooked or missed recording parts that would have made a big difference in the quality of the video. Next project I will do it all. As a spoiler, I already have my donor vehicle...

[@ugd240000]

it would be great if you make more videos with

[@joetheman357]

Great video. Who did you go through to get the wiring harness? Doesnt seem nearly as scary with how you explained it. Dpimg this swap on my 96 w/t 4.3 soon. Appreciate the info. New sub

[@laurencevillegarage]

I used Chris at easyefisolution.com to rewire my harness. He did a great job and I provided a lot of info to make sure it would run well. Of course, in the truck with a laptop or on a dyno would be optimal, but for a basic tune, I cannot complain. I was very intimidated as well. When I got the harness back, looked it over, then installed it on the motor, I was not quite as intimidated. I plan to do my own harness on the "shop truck" project I am starting.

[@joetheman357]

@@laurencevillegarage appreciate it, thanks man

[@Lalomoran24]

Real helpfully 👏👏👏

[@chuckgorman103]

Great details! Does your 5.3 pcm know when you are in park or drive? Or is the signal from the shift module going only to the dash? I might be looking at this incorrectly but the ls and Tbi modules use a different signal common, ie one switches a ground signal the other switches a positive signal. Doing a in series spice like the vss would lead to a dead short i believe. Thanks for taking the time to document your work!

[@laurencevillegarage]

I did splice the four wires that connect to the lower part of the trans module from both harnesses. If you don't something is not going to work. The LS wires need to communicate the trans position to the pcm and the original wires are needed if you want the illuminated PRNDL to light up and show you your gear selection. If yo did not connect the original wires, trans will function fine, but you won't be able to see it on the dash. No issues with the splicing. You can always check with others to see what they did to make their dash lights work correctly. This is but one reason why I advise to not cut or remove any wires until everything works the way you want, then thin out wires if you want.

[@eduardojaramillo9973]

Could you go more in depth on how to get the tach working ? I also have a 95 with 4.8/4l60e. Thanks!

[@laurencevillegarage]

Yes, on mine, the tach wire comes off the LS harness (red C2 pin 10) and goes to the white wire on the OBS stock harness that goes to the coil. On mine, there was a white wire with a spade connector a few inches from the coil. It was not readily visible at first. That’s all it took with my combination.

[@federicomedina1554]

Man thanks for all that info!

[@yousefharrassi5365]

Thank you, this video was very much helpful, as I am planning to swap my current 1997 chevy Tahoe to 2002 LS. but need to know something: what if I get the hall wiring harness from the existing 2002 Yukon XL and fix it to my 1997 Tahoe, is that will be batter or to order new wiring harness.

[@laurencevillegarage]

That is what I did. At some point in the future (way down the road), ordering up a new harness may be preferred just because the old harnesses will be 30+ years old and may be questionable. But, for now, let your wallet (and common sense) be your guide. If you have a good harness, then modifying it makes sense to me. If this is your first swap (and you plan on doing more in the future), then consider (if you feel confident after much research) to go at it yourself. You will want to do your research. I was timid and had mine modified by easyefisolutions.com. After getting mine back from Chris (great guy and did an excellent job), I looked it over and it sunk in that I could do this. The first time is intimidating, but I will be doing my own coming up soon. There is a lot of great info to help you out there. I would suggest going to lt1swap.com and reading everything Brandon has then check out his youtube videos. That will give you the confidence you need. And, if you do try it and it doesn't work, you can still send it in and have it modified. It will still probably be cheaper than buying a new harness and the experience and knowledge you gain is worth tons!! Good luck.

[@kevndo]

Great video. Lots of information. What size are your wheels and what are the offset specs?

[@laurencevillegarage]

The front wheels are 17x7 with a 4" bs, the rears are 17x8 w 5" bs.

[@glendonbenoit5766]

@@laurencevillegarage do have fb looking to get some info from you thanks

[@juicy1426]

For the vss I just cut the purple and green wires from the old tbi harness and splice them to the purple and green wires coming from the pcm? So then the plug is connected to the ls pcm

[@laurencevillegarage]

I basically did the same thing, just spliced them in at the plug.

[@LL-be3rh]

Great info

[@kerryhunter6304]

Amazing video subscribed ... Can I ask where you got your standalone harness and how much it was

[@laurencevillegarage]

Thank you, I had my harness modified by Chris at easyefisolutions.com Including the vats removal, etc, wiring for twin fans etc, ran about $560. While not cheap, when you get it back from him, it is ready to install. I would highly recommend going that route. It will save you a ton down the road.

[@MichaelKnight-z2e]

Hello great and informational video. I'm having trouble finding videos on the wiring of the speedo and tach with a stand alone harness. I looked at the autozone site and didn't see any schematics for instrument cluster, any ideas?? thanks

[@laurencevillegarage]

I apologize for the delay in my response. A factory GM electrical manual for your year truck is very affordable on Ebay and is extremely helpful. For the speedometer, I spliced the vss OBS wires with the vss wires from the LS engine harness and that worked for me. Depending on your year, it may or may not. The tach was easy. On the OBS harness, there is a plug that attaches to the coil that has a white wire within the harness that is not used that is very close to the coil. I used that for the tach signal.

[@juanieto810]

Thank you for your great video! How did you mount your new pcm ?

[@laurencevillegarage]

I used some angle iron cut into smaller pieces to make a bracket to mount to the top of the driver side fenderwell.

[@rakanarbmyh1230]

Thank you very much for making it easy for us gmt400 owners, i have a question about the AC system, do i run the ls compresor with the original truck harness?

[@laurencevillegarage]

Rakan Arbmyh I am going to say probably not. The compressors are different, pcm’s are obviously different but because of the parameters that are tunable in the late model pcm’s there are many differences. Having said that “is it possible?”, with some creativity maybe so. I’m sorry, I know that all sounds vague. In my ‘95, I did use my old harness to run the a/c. The new harness had no a/c wiring. What you could do, and I plan to do on my next project, is to use the ls a/c compressor either mounted low if possible, or use an available adapter to mount the ls compressor in the upper position keeping the factory wiring to run it. Would still have to wire my existing on/off switch in. The factory has some nice settings inside like: cuts off compressor under wide open throttle, automatically turns on an electric fan when a/c is turned on and will alter idle rpm’s when turned on or off.i would like to incorporate those features in my next project. Good luck.

[@caseymaxwell7645]

Great video I’ve referred to this a few times, did you leave original ecm still in truck or take it out completely

[@laurencevillegarage]

I left the original ecm in the truck. I only cut back the wires that were not needed in the trucks main harness. Notice I said "cut back", not remove completely certain wires. Could I have removed it? Maybe, but it would involve a lot more work and 99% if people looking under the hood would never know the difference. Functionality, all my gauges and lights work like factory. I don't want to create a problem where I don't already have one. If you are dealing with a basket case and have a lot of damaged or missing wiring, that would be different. But, for me, working with a decent truck to begin with, I chose to cut and remove as little as possible. Remember, in the future, you will have to work on the truck. Or, if the truck gets sold, someone is going to have to figure out problems with no idea of what was done to it. I thought the least I had to remove/alter to make everything work was the best choice.

[@wnbmechanic4127]

hi i just found your channel thankyou so much for the info. i have one question though what engine mounts did you use? i also have a v6 obs and I only find motor mounts for the trucks with the 350s. Thankyou once again!

[@laurencevillegarage]

Thanks for watching!, try metaltek manufacturing for the mounts I use. Search this on ebay... 1988-1999 C1500 TRUCK K5 2WD Engine Mount Adapter Swap Kit LSx LS1 LS #14055KU

[@wnbmechanic4127]

@@laurencevillegarage Thankyou so much man. Your really helping me and dad with our project Thankyou!

[@amiranda3444]

Hi sir , where or what pins or color did you hook up the 3 wires to at the pcm harness? Thanks for any help

[@jamesphillips8518]

I have the same truck as your's .My swap is almost done I only have 3/4" play on my slip yoke on my drive shaft was your's that way '""'''''

[@williamlaurence4355]

Mine had a bit more than that. Since I used sliding motor mounts, I mounted my transmission in the stock original location and then fixed the motor location based on that.

[@jesserosas3157]

Outstanding video !!

[@laurencevillegarage]

Jesse Rosas thank you, I hope it was helpful.

[@luckylarryrebuilds8604]

Hello saw your video inspires me to do a swap in my 95 obs. have a question did you use the ls AC compressor or did you use the OBS AC compressor did you have to move location? And fuel pump which one did you use? Thanks

[@laurencevillegarage]

Thank you for the questions, you can go with the AC Delco EP381 fuel pump and it should be a direct replacement for your existing pump within your tank. This is what I’ve used for my swaps. You can use AC Delco, or Aftermarket, that would be a direct replacement for that pump. Easy to do. As far as the AC compressor, at first, I used the R4 compressor from the 95 because it worked. I modified the existing factory bracket so that it would work. Had trouble with the R4, so upgraded to a sanden style compressor. At that point I sold the truck, and they install that compressor using a dirty dingo bracket kit that I supplied with it still using the existing are for factory bracket as the base. In the 91 truck I currently have, I wanted to keep the AC compressor in the factory location, the lower mount side. A factory GM compressor will not fit. I used a dirty dingo, sanden style replacement compressor that is several inches shorter, and it fits just fine. However, having said that, I did have to modify the side frame rail for clearance. Check my other videos, I did make a video showing the different styles of AC compressors available that you can use, and also a video showing how I installed the dirty dingo compressor on the 91. Good luck.

[@luckylarryrebuilds8604]

Thank you. appreciate the feedback I will definitely look into your other videos on the AC pump.

[@masonstevenson1334]

I have a 1989 k1500 that I'm doing a 5.3 swap in. I'm wondering if you took the old computer out completely. Or was it needed?

[@laurencevillegarage]

I left it in and just thinned out some of the unused wiring. I still want everything on the truck to work as original. And, it does. Be sure to not cut or remove anything (if possible) until you have your vehicle running. Then you can thin stuff out. If something stops working you have a better idea what and where to look for the problem. If you delete too much in the beginning, then have issues, it will be much more difficult to track down the issue. Don't remove any grounds, I found that out the hard way.

[@murraymcglynn454]

Thanks for the vid , I`m about to start a swap(2004 denali 5.3, 4L60 & tcase-into a `89 short box 4x4) .My question is ... how long did it take you to install motor and wiring to turn key?

[@laurencevillegarage]

Keep in mind, except for modifying the wiring harness and charging up the a/c, I did everything by myself. I had been accumulating parts for nearly a year. I actually pulled the motor out of the '95 in mid January (I believe) and had the truck running within a couple months. I was also working full time, grandkids, honey do's, etc. I am just now finishing up little stuff to make everything "right". If I had been working on it "full time", I would say a less than a month. But, you will find that you need a certain part and after ordering it, you get it a week later. For example, I rebuilt my exhaust system 4 times before I got it the way I wanted it...Ordered by 4th belt.....stay with one brand, do not try to compare gates with dayco, its like comparing levis to wranglers. I am also very picky, I want it to look clean, organized and reliable. Good luck, it has been a very satisfying project.

[@murraymcglynn454]

@@laurencevillegarage Thank you for replying ,Murray, Vancouver BC, Canada

[@JesusGarcia-bj5yp]

Nice video, bro. Thanks I like it. Listen,I did my 93 Chevy C3500 with 4L80E and 5.7 I swap for a 6.0 and I did the Harness by my self. Ca you told me how to connect the OBDII port. Please

[@laurencevillegarage]

I would have to see your specific wiring harness diagram for the truck AND for the year of engine/harness....but, on mine, the '95 truck harness data link wires show to be tan and white/black...for your engine, it will depend on year and whether it is DBW or DBC and what year it is. I am going to guess it's a gen3 motor... if it is DBW look for a blue/white wire pin 15 and orange/black pin 14 on the blue C1 connector...if DBC look for #58 pin dark green wire. Hope that can give you some direction.

[@JesusGarcia-bj5yp]

Thanks so much. Mine it’s Gen 3 ,2003 drive by wire

[@aboremas7107]

this is the best explanation 5*

[@laurencevillegarage]

Thank you!

[@5809Alejandro]

Very good video grrat explanation do you know where to buy a harness for my 96 2wd silverado to 5.3 ls swap

[@laurencevillegarage]

If you have the engine harness that came with your 5.3 you can get it modified if you don't have a harness, one can be purchased from a variety of vendors who cater to this market. I sent my harness to Chris at easyefisolutions.com and he modified mine to work great. You can also purchase a used (ie salvage yard harness) that is at least close to your application and send that in and it can be modified as well. You did not mention if you have a pcm. If you have the one that came with the 5.3, a variety of sources can reprogram that for you for under $100 (depending on the extent of your modifications). If you don't have a harness or pcm to begin with, it will be more expensive. You can contact a supplier that will be glad to make a harness for you and supply the pcm. It will be more expensive. Need more details to be anymore specific than that. Good luck.

[@lachuma508]

This is a great video good job thank you what kind of drive line you used?

[@laurencevillegarage]

Thank you for watching. The donor was a 2002 Chevy Tahoe, 5.3/4L60e using stock "96 driveshaft and 3.42 rear-end.

[@lachuma508]

@@laurencevillegarage thanks for the response, reading again and I'm a little confused your using the stock drive line out of the donor vehicle or stock drive line originally in the 1995 truck?

[@laurencevillegarage]

@@lachuma508 The engine and transmission are from the 2002 Tahoe, driveshaft and rear are from '95 truck. The engine is basically stock, but has a BTR stage 1 truck cam/springs/seals with a free flowing exhaust.

[@rayleemck]

Amazing video. How did you go about thinning out your harness

[@laurencevillegarage]

On that '95, I only thinned the old unused wires back to the main wiring bundle...just in case. On the "91 I am presently working on, I am pulling out all the old unused wires back to the firewall. However, until all the "sorting out" is done, I done permanently remove any of it. Once all is good...ie gauges work etc, I leave it in case I need any of the "old" wires.

[@rayleemck]

@@laurencevillegarage any videos of you talking about how you did. You have a way of explaining things were people who are new to this get it

[@rickiimartinez9346]

Great video

[@garydevlin5325]

Great video keep it up👍

[@laurencevillegarage]

Thank you Gary!

[@jacobspeights3163]

Awesome video what oil pressure sensor did u use and plug ?

[@laurencevillegarage]

I used an adapter to use my original c6 sensor. I did the same on the ‘91.

[@texasnavy12345]

A little off topic, but what drop did you use on this truck? The stance is perfect! Wheel/tire spec?

[@laurencevillegarage]

Thanks Robert, It's a 2/4" drop. I used DJM 2" drop lower control arms with matching uppers to keep my stock springs. I wanted to keep the factory type ride without killing the ride quality. The rear uses 2" drop hangers/shackles. The wheels are American Racing VN205's, fronts are 17x7 w/4" bs and rears are 17x8 w/5" bs. Tires are f 235/60-17, rears 265/60-17 Faulkens. No clearance issues front or rear and rides very nice. I wanted a 4" bs on the rear for a deeper look, but (with a straight edge on the face of the wheel) it would have made contact with the wheel lip if suspension compressed enough. So, went with the 5" bs. Thanks for the compliment!

[@younggunn7907]

Helluva video great job great detail

[@laurencevillegarage]

Thank you, hope you found it helpful! Good luck on your project.

[@thomasblais7751]

Ur a legend

[@misterwhite235]

Thank you

[@mauriws6ls1]

Did you modify any of the factory a.c wiring or you just plugged everything back in place after the ls swap?

[@laurencevillegarage]

I was able to plug everything back in. However, when going that route, any of the LS pcm a/c functions are not going to work because the signal did not go through the pcm.

[@MrGto05]

Quick question, the ground you were talking about for the fuel level sensor, was it in the main harness or the harness coming off the fuel pump itself? Great video by the way and that is a nice little truck!!!

[@laurencevillegarage]

That ground (as I recall) is in the main harness. You just want to make sure all the original grounds are kept and grounded properly, and you should have no issues.

[@MrGto05]

@@laurencevillegarage thank you so much!

[@MrGto05]

Well I finally got time to poke around that harness and found the ground! Thank you once again bud!!

[@marlonbarrentine6268]

I have a 92' GMC Suburban K1500 4X4 with 700r4 Trans & 5.7L TBI engine. I also have a 5.3L LS without wiring harness or computer, I got the 5.3 in as a trade for some parts I wasn't going to use. I would like to swap in the 5.3. What parts did you use for the fuel system? I will take your advice on the wiring, as it's the most comprehensive I have seen for the TBI trucks. Also, I'm not quite sure which direction to go for the Trans and Transfer Case, any suggestions? The truck will be used for hunting trips and towing a dog trailer. Where I live, emissions is not a concern. Thanks!

[@laurencevillegarage]

First, did you get the automatic transmission flex-plate with the engine? If so, your are in luck. If not, you will need to get a dished automatic trans flex-plate for a 4.8, 5.3, 6.0 and an adapter. If you google "ls swap automatic trans adapter" and you will find plenty of information. The cost of an adapter ranges, but usually $35-50 will get a good one and you'll need new bolts as well. Finding a used flex plate is easy enough, ebay has them starting (used) under $40. So, flex plate $40, adapter, $35 and bolts (prefer new) $20-25 and you should have what you need to match up the engine to your existing trans. The fuel system, does yours have a return line? Either way, I went to a local shop that makes hydraulic hoses. They made me up a pair of lines while I waited for about $90. There are kits available. You can spend $100 or $300, so shop it around. All depends on what intake you are using, return fuel line or returnless. IF returnless, a simpler system can be used. Again, google fuel lines for ls swap that will match up with your intake style. You will need to upgrade your fuel filter. Just get an acdelco replacement for a '96, it will drop in. Also need to replace any other rubber hoses in your fuel system (that are under pressure) with a higher quality higher pressure fuel injection rubber hose. Wiring will be as simple as it will get since you don't have an electronic trans, no emissions and engine only. You did not mention whether again, the intake style has a Drive by wire or Drive by cable.

[@marlonbarrentine6268]

@@laurencevillegarage Thanks for the reply and info. It will be drive by wire and the current engine setup has a fuel return. I can't remember which intake came with the engine, but I'll check it.

[@c1poweredeg]

Did you change anything on the engine harness? Or was it just the 7 wires that needed to be connected to complete this swap?

[@laurencevillegarage]

Yes, the harness is modified. All emissions removed, rear O2 sensors removed. It will all depend on what engine you start with and the vehicles purpose. Depending on your state, you may need to keep some items to remain in compliance with state laws. About half of the original wiring was thinned out.

[@chappyboylsx2596]

Can you tell me what you did for your fans,how many you running? And what are your turn on and off temps for both?? Thanks again. .

[@laurencevillegarage]

When I had my wiring harness modified (Chris at easyefisolutions.com ), wired it for twin electric fans. I purchased a set of "clone" 2010 Camaro electric fans and had Chris set the pcm to turn one on at 185 and at 195 degrees. If you plan on running a/c, let the one modifying your harness know this. Depending on which pcm you use, there are other features that may be altered. I say "may" because the LS based pcms in the early trucks had engine mounted fans, not electric. Whereas the cars, I believe all had electric fans to begin with. Features such as increase idle when a/c is turned on and to automatically turn on a fan when a/c is started. The latter, I have a video showing how to wire in a fan relay. Many people seem to be running ac with their LS swaps, yet no-one seems to break down how to do it the best way. I don't recall going into detail with this with Chris. If, I have someone build my harness next time, I will ask more questions. The first time, I didn't know any better.

[@mayito2651]

Did you use the stock transmission? I have a 92 4.3 and I’m going to do a 6.0 swap, will the transmission in it hold up? Is it the 4l60?

[@laurencevillegarage]

No, I did not. I sold my 4.3/auto to help recoup some $. I used the transmission that was paired with the engine in a 2001 Tahoe. Yours is probably a 4 l60, it won't last behind the 6.0 IMO. With the 6.0, you have choices, but a 4l80e would be a good combination. Depends on what you have available. An older trans will work as well as long as it is strong enough for the 6.0 and uses an adapter.

[@Funtimes670]

My TBI 350 has ticked me off to the point I’m ready to start the LS swap. I plan on buying a complete running suburban and having it available until I complete the swap just in case I need anything else. I was wondering about your AC, did you modify your v6 bracket to work?

[@laurencevillegarage]

That's how I did mine, but with a Tahoe. The only way I will do it in the future. Yes, I modified my existing a/c bracket to work. It's not hard and positions it perfectly with the alignment of the ls truck accessories. I will also put a link below the video to my facebook build page. Search the internet for maliburacing.com and in search look for the r4 a/c bracket story. Great pictures and description of "how to", that's what I followed. Good luck!

[@laurencevillegarage]

Here is the link.....l.facebook.com/l.php?u=http%3A%2F%2Fmaliburacing.com%2F%3Ffbclid%3DIwAR0wFcy8xysulF_3J29QC6aZ6iG0dZjEB7rsZxv816L8KW9rrmmffqWSxSc&h=AT25AYMeI8-F7GcXjFCcB0X5cMGSbKXx8OkIeriu-DbKHZtgg07UIOqlzU-PgS2wbPUQBMZF49F9x8G2fhPbVbW74El_k2mTnkzGZKHO2_bxDi1zkq3fif4ESjJ9cYxFqxAUjAOZaJLZs-q3Ww

[@laurencevillegarage]

the other link is a bit broad, this is more specific, sorry....www.maliburacing.com/forum/viewtopic.php?f=34&t=79059

[@Funtimes670]

Cool, thank you very much!!

[@brianbonner8069]

Thank you for the great video. I have a 97 k 1500 with a 4l60e will the 5.3 bolt up to it? Will I need a spacer?

[@laurencevillegarage]

Yes, you can use your trans. You will need a spacer kit, around $50 with bolts. Should not be a problem.

[@brianbonner8069]

@@laurencevillegarage Thank you very much!

[@jeriusbearius]

I cannot thank you enough!!!!!!!!

[@laurencevillegarage]

You are welcome, glad it helped!

[@salvadorestrada7097]

Hello! First off great video. I'm in the middle of doing a swap in a 91 c1500 . How ever the doner 02 yukon was hit at the fuse box side causing wires to be torn at the fuse box. All the wires going to the PCM are still in contact and connected. Do you think I can still make it work or would I need a stand alone harness at this point? Thanks!

[@laurencevillegarage]

The short answer would be, yes, as long as your harness is not damaged badly, you are ok. Do you plan to rework the harness yourself or send it out to be modified? In either case, any damaged wiring can be fixed. It will really help if it’s all intact w no plugs missing. Just try to keep your complete engine/trans harness intact and you should be fine.

[@salvadorestrada7097]

@@laurencevillegarage right on thanks! All the plugs are there I took them off after removing the 8mm bolts holding them on the damaged fuse box, but as stated some are damaged and dangling at the ends but over all the harness is all one piece. I'd like to save me $ and work it my self but at the same time I might be better off sending it out to someone but don't know who. Will see. But for now I'll keep wrenching till I get to that point

[@laurencevillegarage]

I used easyefisolutions.com for my harness, Chris did a good job. I had him wire in dual electric fans as well. Took 7-10 days.

[@salvadorestrada7097]

@@laurencevillegarage thanks I will send them an email and see what they suggest. Any questions I'll get back to you

[@juanroaroa58]

Thanks

[@Michael-White]

What company mated your old wiring harness with the new 5.3 wiring harness?

[@laurencevillegarage]

I had easyefisolutions.com to modify my "old" harness. When it comes to integrating the "loose" LS wires into the trucks harness, that is where "you" come in. It will be a bit different on each truck or car. You need a wiring schematic for your vehicle to make things a lot easier.