OBS GMT400 Electrical Issues? Replace Your Ground Straps!

[@WeakestofWeeks]

Turns out my workaround for the fuel filler ground repair is incorrect! My way just connects the bed together in 2 separate places which is rather useless. The proper way is for the actual metal filler neck to be grounded to bed. kzbin.info/www/bejne/qmnUZpaheL6KpLM is the updated video for the filler neck ground strap

[@dropdestroy]

Was gonna say lol. Honestly easiest way is just to swap the neck. The strap is riveted on.

[@mr.createandfix5504]

Might keep static from igniting fuel vapor. I think thats why its there

[@brandonrobishaw7606]

I did that before and my fuel pump didn't work anymore It was grounded through the filler neck

[@slownloud9743]

Much respect man, js you actually acknowledged the mistake and didn’t just leave us all hanging lol 💯

[@TradeWorks_Construction]

Yeah so was going to comment on the very same point. Due to the plastic surrounding the filler neck and the insulation padding between the top of tank and body it doesn’t have a very good electrical connection to the chassis/body. So making certain a ground strap directly makes connection at the filler neck helps bond it back to the rest of the system. If I’m not mistaken the fuel lines transition to a flexible rubber section for a few feet before connecting to the fuel pump assembly.

[@limited50scla]

Forgot about this video, cleared my watch history and search history due to stupid videos in feed on KZbin. This one popped up again 🎉 Went to the junk yard and pulled 2 grounds from a OBS, which had the engine and radiator support removed. Measured the length of the grounds straps and the diameter of the ends. Going to get some battery cables and a power to fuse cable made along with the grounds. Cheaper than going to dealer ($400 for all the cables minus the grounds ) 👌🏻

[@SummitScene]

Thank you! This is an outstanding tutorial. I now feel much more confident in my ability to troubleshoot and fix the electrical issues in my 1992 K1500. I bought it brand new at the end of 1991 and it is still serving me well at the beginning of 2025!

[@DocZoidberg549]

I have three late 90's OBS's, I have replaced most of them. I have worked on GM products for 40 years, they all have the issue. Great vid for newbies.

[@migoabu3928]

What r the issues they will or could have ?

[@DocZoidberg549]

@@migoabu3928 There are a few. It's hard to list them out in the comment section. Single issues are much easier to explain.

[@mark98070]

Is this also the case for the GMT800s?

[@DocZoidberg549]

@@mark98070 Yes

[@DiegoLopez-ii7ve]

How many are in total, beside these ones, saw one little wire from the Neg to the inner fender... also with the ones that goes inside the cab..!! Appreciate, im replacing all of them before chasis swap

[@michpatriot9097]

When I started doing this to my suburban I got to a point that it really had gotten boring..so to fix this I had the wife come out and drive to the grocery store..it makes all the difference doing this job on the fly! First make sure all your creeper wheels are in good shape, it helps to grease the little axle thingies to keep em rolling at the speed they will need to. Then a good bungee cord to attach the creeper to the cross member so that when im on the freeway the creeper don't get squirrely. The breeze helps to keep the debris from piling up around my eye sockets I've noticed..speaking of sockets..I've found those little magnet trays work well as long as you can find a spot to stick them where they are accessible..the trans pan is steel just like the driveshaft where I first tried. After she turns right hand corner(not before) is the easiest time to reach behind the passenger side tire to get the ground strap up by the heater hoses..I had her pop the hood at a light to get the one on the rear of the cylinder head( keep yer belt buckle out of the fan area) and then once you have that one done and the light turns green, shimmy back on the creeper so as you can coast back to the one near the driver side rear tire on the gas fill tube. Now this one I won't lie was grizzly, what with the tire whizzing around right by my cheek..but that O'Reilly's bungee cord kept the creeper just positioned perfect for me to reeeeach up and get the nut on! Then I shimmy slid back up to the trans pan for the last bolt in that handy lil magnet tray to finish the job. Way more fun!!!!

[@chefman45887]

Replacing all of my straps tomorrow. On my 88 3500 , the worst one to reach/remove is the one on the back of the passenger cylinder head. Also when removing the nuts and self tapping bolts spray them down with PB blaster or WD40 a day in advance to make them easier to break loose. Solid video , thanks for sharing!

[@davidsartin5708]

You missed the idea of the first ground strap. It is there to ground the metal filler pipe to the body ground to prevent a static spark. All you did was to ground the body to itself. The cup inside the filler door is plastic on most vehicles. You need that ground strap to be grounded to the metal filler tube.

[@richardbuchli4071]

I am fixing to go outside and start checking the grounds on my truck. Believe I also have a short somewhere. Thanks for this tip.👍

[@Arkansas223]

@@richardbuchli4071Do a Big 3 or Big 4 Upgrade and then upgrade the grounding factory grounding straps and you will be good 🔥

[@jw11432]

Oh, this applies to every vehicle lol I've got an 02 Silverado (GMT800) and when I first got it form my uncle (his old work truck), he said he couldn't use the AC because it would cause the instrument cluster gauges to stop working. I knew immediately if it wasn't a faulty AC component, it had to be a bad ground. So I replaced every single AC component (compressor, evap, condenser, lines, sensors) and wire wheeled every ground to chassis/engine I could find. My AC works beautifully (after some bad parts issues; stay away from UAC parts!!!) as do my gauges.

[@Dagrizzb]

The UAC compressor, was it an HT6 style or Sanden style?

[@jw11432]

@Dagrizzb my compressor is actually a 4 Seasons brand. The UAC part was the condenser line (the one that went to the top of the condenser and I believe to the compressor). But the style is neither that you mentioned. I think on mine it's 10S17F? The HU6 I think is the single manifold style (as opposed to two separate lines bolted individually on compressor) and I'm not even sure about sanden style.

[@kenwinchester]

I have a 1998 Chevy K1500 with the 350 engine and I do a lot of my own maintenance. This has been a great video for me. I will check my ground straps for integrity and replace if necessary. Although I’m not quite to the level as you for OCD I do tend to overthink sometimes. I’m very impressed with your quality of video and presentation skills. Thanks for your efforts and I did subscribe.

[@WeakestofWeeks]

Thanks for the comment friend!

[@codysteele9889]

​@@WeakestofWeekswill the ground strap near the fuel pump cause the fuel gauge not to work? I Just replaced the fuel pump an I seen a old ground strap that's broken everything works but the gauge would that be my problem? Please help I'm lost now

[@KarenListo]

Will a bad ground effect the cam position sensor low voltage.. or maf low voltage

[@diamonddave8938]

Great Video! Thanks. My 98 K1500 has another ground from the fender near the battery to the front of the block, under the alt.

[@WeakestofWeeks]

Thanks for sharing! I'll have to take a closer look at mine

[@Ace-44]

Really appreciate the video. Was able to complete this because of this video. I used a 6 gauge 20 inch ground strap from Walmart for the frame to the back of the engine. Was big enough for both sides.

[@daehr9399]

2:31 I feel your pain. Oh the countless hours I have spent under my truck getting rust in my eyes pains me. Definitely always wear eye protection when working under an older vehicle.

[@dougedwards8022]

Yes sir you are correct on this topic 120% an the newer trucks are even worse,,,,as soon as 5 to maybe 7 yrs from new grounds start causing problems,,so many run down running an performance problems an think they have them fixed an will be for a short then all the sudden same problem or more is back,,,and most if not all the time its a grounded issue,,the issue is that when the correct ground is lost the parts in question starts looking for another ground,,so it keeps on keeping on meanwhile overloading the ground it try to use,,,an now you have more issues,,,after throttle body fuel injection entered our lives ground became more important than ever,,,,

[@billkraemer4710]

In drier locations, even the ground bolts should be removed, cleaned with the nut holes cleaned. Apply no-ox and retighten. Many of the sensors work on just milliamperes of current and a dirty ground will be just the start of all manner of problems. Clean and or replace the grounds straps.

[@martinkolff5606]

Don’t want to be an ass but your fuel filler neck is made out of metal and isn’t grounded anymore. You grounded the side panel to the frame which is allready grounded. Maybe you have to try to drill out that rounded bolt and put in a bolt to secure the strap.

[@WeakestofWeeks]

No offense taken and I appreciate you respectfully pointing that out! You're totally right though I didn't even think about that. Basically right now I just connected one portion of the bed to a different section which is pointless. Since there is a plastic piece in between the metal filler neck and that inner metal bed side, I bet that's why that grounding strap is there in the first place. I'll work on an update to correct. Thanks!

[@martinkolff5606]

You’re welcome. Just wondering why you did that in the way you did. But he. It’s not a Saab. Like your videos about that and learned a lot of it. To bad we don’t have scrapyards here you can walk into. I have a 2003 93 sedan with an 1.8t engine. Actually it’s the same 2 ltr engine but tuned down to 150 hp. Tuned it now to 225. Brilliant. Keep up the nice work.

[@joneastman5627]

I was wondering about this an thanks

[@michaelwebb8348]

im pretty sure its primarily there to ground the fuel tank and prevent spark, and also the fuel related pumps and relays

[@nickoD509]

@@WeakestofWeeks Probably just use a hose clamp around the tank neck and ground the wire under it and tighten it. My easy idea I had without having to messing with any bolts.

[@d4ve587]

I love those old trucks usable classic 😁

[@victoryfirst2878]

YOU should use stainless steel or bronze bolts. Then anti electric grease and finish with silicone RTV sealant to finish off the job. That works great fella. P.S. solder the terminals and forget the shrink tubing. That is what I did Sir. Cleared up a lot of problems with strange codes that surfaced. They all disappeared....😀😀😀😀

[@JamesSmith-xs7sr]

I removed, cleaned all my grounds, treated them with Deoxit spray... T stat housing ground went from .3 volts to .05 volts, engine running. (98 GMC Sierra)

[@MyLifeThai371]

You could have also used a dremel rotary tool to slop out the eyelet holes.

[@stevemas4966]

Great Videos, excellent mechanic

[@tarbeau8561]

Thanks for sharing this video and where to find most of the hard to find grounding straps. Also, not having a hooked up ground, would that drain a battery? Thanks in advance. My battery keeps dying and getting drained. I've replaced the battery, starter and had my alternator checked out. Still get drained batteries. So, I installed a manual power cut off from my battery to my starter and (knock on wood) no more problems with dead batteries. Thanks again for any help

[@JamesSmith-xs7sr]

Get a cheap multi meter, go inline negative circuit at battery. Under 50 miliamps is fine. (.050 amps) If its higher, start pulling fuses, watching for amp drop. When you find the offending fuse/circuit, get a wiring diagram & isolate the culprit. Google parasitic draw testing if you need more info. Once understood, its easy on these older vehicles...Make sure you understand how to set the meter up proper.

[@marvinrussell7763]

The ground wire connecting to the gas tank neck is to keep from having a spark whenever you put the gas nozzle in to fill your car up. Connecting to the door does not work.

[@ZIGZAGBureauofInvestigation]

Yeap USE the hole to the right ! as a ground. Not the body of the truck.🔥

[@KYoss68]

The first ground strap is to ground the filler neck to the body in case of ESD when fueling. Your change in the location basically grounds the bed to the bed. I hope you move it back.

[@MiamiWebDesign]

Great video, thank you. I'll be doing this to my OBS Tahoe asap!

[@williamtowery3586]

Thanks for the information,much help

[@americanwhiteboy715]

My stde broke of and I looked for a stud bolt that I could use to go to the firewall and it broke now I found one up a little higher like in the video would that be a good stud to use for the ground to look at the stud above the heater hose on the bracket

[@savoielvis1]

Thank you!!!

[@weirdgamerincxpected2882]

You have to run the drill in reverse to drill eyelets bigger will get very hot however it'll drill there with ripping it.

[@WeakestofWeeks]

Good tip, thanks for sharing!

[@LarsonFamilyFarm-LLC]

I have a 1989 GMC Sierra Truck...most important ground...is the fuel pump's frame ground....if that ground is semi-faulty, higher resistance it'll chew up pumps in a few months to a year. So just to make sure I ran a heavy 12-awg ground wire from the tail-light frame ground, trailer plug's frame ground and fuel pump frame ground to battery ground. It solved all those problems in the rear of the truck. Frame grounds...don't like them, they are secondary....I like grounds to the battery post or 1st frame ground point.

[@blackjackshooter6547]

Thank you so much for sharing

[@bwilly56]

You grounded the bed to the bed! Good job buddy!

[@WeakestofWeeks]

Think you meant dummy not buddy lol. It's been resolved tho kzbin.info/www/bejne/qmnUZpaheL6KpLM

[@waltercardenas7354]

Any idea which is the ground for the fuel pump? My gague is dancing . Thank you

[@DigIntoGaming]

I have the same issue and heard that it's might be the air core stepper motor.

[@JorgeFelixbeltran]

Sounds that you have a faulty gas sending unit. I had the same problem in my 1990 Cheyenne pickup sending unit was replaced and fixed that issue.

[@MikeDGreat30]

Any luck?

[@LCLj73]

Thank you for this video 👍🏾

[@Gruin]

Any attempt to drill something That has a previous hole in it as in your strap, I run the drill backwards, It's slow but it works.

[@Jayc-32]

If the ground is cut in half will it not start ?

[@craigescapeddetroit5198]

I would coat all the ground straps with some grease, as well as all the nuts and bolts.

[@racer67]

So there was 3 ground straps total?

[@montestanley9216]

Isn't it supposed to connect to the fuel pipe?

[@buickrepairs1713]

How does that ground the fuel tank at all? Where you put that new ground seems to have no metal connection to where the old one was. You're connecting the body to the body..

[@WeakestofWeeks]

One of those things I didn't realize until after the fact. I ended up redoing the filler neck ground to connect it properly: kzbin.info/www/bejne/qmnUZpaheL6KpLM

[@alexobs13]

So the two ground straps under heater hoses you only kept one ??

[@WeakestofWeeks]

No, I removed 2 and replaced with 2 new ground straps. There is one that goes from the frame to the firewall under the heater hoses. Then there is a 2nd that goes from the same frame location but to the back on the engines cylinder head.

[@alexobs13]

Oh ok cause I have two ground straps under my heater hoses I have to check the one in the back of the motor. Checking all my grounds cause I’m not getting any power to the passenger door on my 91

[@Angell365]

I have a 1998 obs chevy, has a problem starting, changed the battery, changed the alternator, changed distributor, did the timing belt and still wont start. Had a mechanic told me it could be something electrical any advice?

[@codysteele9889]

Will it start with starting fluid? How is it coming out of the injectors dripping or nothing at All?

[@JamesSmith-xs7sr]

Connect a fuel pressure gauge at the test port. Key on cyle should yield at least 60 lbs. Crank engine over. Turn off. Fuel pressure should remain somewhat constant for at least 15 minutes. If it drops instantly, you have a bad fuel pump check valve, leaking injectors, or faulty fuel pressure regulator. Look inside the throttle body. If you see/smell raw fuel, pressure regulator is likely at fault The Injectors need around 60 psi to pop off/run the engine.

[@chizzlebeatz]

ignition switch?

[@mattanello414]

Starter? Lol

[@andreconstantineau7104]

If it struggles to start on rainy/humid days, could be the ignition coil. You can test it, or just replace, not very expensive. Delphi CE20003 Ignition Coil

[@chizzelfingers]

the ocd is great. I'm the same way. I'll turn a 15 minute oil change into torque specing random bolts,cleaning thongs that will never need cleaned. 😂😂😂love it

[@Hillbilly_Bob.J]

I do the same thing!

[@walterbennett4948]

Would the ground straps on the passenger side cause the upstream 02 sensor on the same side to throw a low circuit code?

[@TheUndertoe]

And if you break the stud under the heater hose you can just get a big self taper and it should snug up

[@blixiee4925]

I took a bolt out of my inner fender and screwed it right in

[@TheUndertoe]

@@blixiee4925 that’ll work too

[@ИльяКузнецов-т7д]

Thanks a lot, bro!!))

[@BPzeropoint]

When my wiper blades are on the transmission shifts! crazy.

[@marktrev747]

Does anyone know the size n thread of the bolt for the frame on passenger side. I think the bolt fell out so I can't ground the wire from firewall

[@mikeanderson7206]

Why are all your ground strays turning blue and green and crumble apart? My 1997 that's been sitting since 2014 are still like new

[@MrOiram46]

Do you need to disconnect the battery first before replacing the grounds or is it fine to leave it connected?

[@KYoss68]

The ground straps only matter when the key is in the on position.

[@cynicalcy]

My firewall ground bolt was already snapped off. What is a good alternative location to ground to?

[@colesbrochuresandtrucks3242]

Mine snapped off as well. All I did was take a wire with eyelets on them and bolted together the wire and the strap and bolted it to the coolant overflow tank mounting bolt. It doesn't look pretty but it works.

[@larrynorsworthy8582]

Where is the ground for the fuel pump?

[@griffinhammond9747]

Any clue why my truck does not have the stud below the two heater hose? I had two ground straps at the frame point but I am not sure where the one went too that should be below the hose. I have a 1999 OBS Chevy with a 5.7

[@benberry792]

$30 ground for the win!!

[@BladeCox]

Is there just two grounds the strap and the harness ground I’m putting motor back in truck and making sure all grounds are covered this diagram I’ve been looking at says there’s there grounds straps that go to the stud behind the left cylinder head

[@adriantee1105]

If I have no headlights and tail lights which ground wire do I look for

[@BenPoythress]

I have a 2000 Chevy Silverado having problems with all interior electrical systems they come on and then they go off. I will try your your way to solve my problem tomorrow. I think that is the problem because I had an asshole change out the motor and nothing worked the day I got it back but he said he didn’t do nothing wrong ha ha ha thank you very much I will try it and I will let you know. Thank you

[@MarshallSmith27]

how did it go?

[@thndr_5468]

Does it not matter if the ground strap is touching the filler neck?

[@alexandrorodriguez1442]

Would you happen too know bolt pattern for frame bolt that holds down the straps ?

[@chizzlebeatz]

cluster still lights up. but the area where it shows your fuel level is dim. which ground would be that?

[@MikeSmith-nu9wt]

In the instrument cluster itself , cold solder job ..i would guess

[@irishuwould5185]

Do you know the size of the bolt for the filler neck ground strap that goes to the frame? I know it’s 10mm but I need the actual bolt size. I’m missing mine. My strap is dangling.

[@Jvremodeling392]

will his cause the light battery to turn on

[@bradyhuey4902]

I have a 98 and I was looking for the ground stud on the back of the engine and the stud, bracket, and wire are all gone and all I see is the hole where it should go. If anyone has any suggestions it would help a lot

[@craigsharpin]

chainsaw file in a drill works good

[@corpuscuhh6598]

Mine is broken off what is that ground for?

[@busterrapoza8668]

You went from the bottom of the bed to the fender, the same ground you did not go to the gooseneck where the metal is your side panel and your gooseneck has a piece of plastic in between it. You need to go to the gooseneck with the ground strap that is to sew itwill not spark or have a static electricity check your work you’ll see what I’m talking about

[@GwinnettLawns]

The ground strap on the filler neck is to dissipate and electrical potential and prevent static electricity from igniting fuel vapor. You need to attach it to the neck as originally. You basically ran the strap from the body to the body which has done nothing.

[@claysteinbrink9559]

Just to let you know you just grounded the body to the body the ground strap going to the gas filler neck is for the filler neck when you stick the gas nozzle into your car the nozzle grounds to the steel gas tube good try awesome idea

[@TheUndertoe]

You can shorten those ground straps just cut em how ever long you want em and crimp a new ring terminal on that’s what I did on mine

[@kevinscheifele6833]

Def not a Canadian truck. My lord thats clean.

[@kinghotrod]

Nut on stud at back of cylinder head is 9/16 on my 1997 GMC, not 14mm.

[@edwardaunchman71]

Bolt 2 shorts to make 1 long

[@stevenm.hollis4429]

Any area this is exposed to elements should be sprayed with a clear coat or a protective spray.

[@clearwaters1974]

lol went from body to body 🤣😂🤣😂🤣😂🤣😂

[@TheUsz28]

Where's the ground in the back?

[@MegaBolens]

Congratulations you grounded the bed back to the bed for the first one and did nothing for the filler neck

[@kurtdussander4944]

Yeah I seen that said I bet half the comments are people pointing it out to him.

[@MichaelMartinez-h7y]

Great. Job. U make. It. Look esey I. What. To. Know. We're. The. Wiers. Go. On. The. Starter. Plz. I. Have. 3. Wiers. Big. Med. N. Small.

[@Speakersbumpin]

Def grounded to self in the back but I have a no crank condition and had a strap hanging under the exhaust no I know it goes up through that tube thanks

[@Obs-junior]

The ground to the filler neck what if it’s not bolted up in my truck do I need it to

[@not.lxtr3l1]

Why not replace it with a ground wire

[@tylergress7297]

That supposed to go the filler neck so the tank is grounded

[@GeraldKooienga]

You’re just hooking the bed to the bed with the first one.

[@lloydsharp7993]

And replace ALL the fuses.

[@Michael-B41]

no you done nothing on fuel tank one........wrong wrong wrong

[@Michael-B41]

your ground to fuel tank the plastic is separating it lmao ground the bed to the bed ok

[@WeakestofWeeks]

Yep realized that after the fact kzbin.info/www/bejne/qmnUZpaheL6KpLM

[@tomreyes4908]

Salvage yard is a good place to find those straps with a fraction of the price

[@CarnageInTheGarage78]

Umm, theres a reason why the grounding straps come uncoated, any water intrusion will not be able to dry out and will cause the straps to rot out faster, and also they use straps like that to allow better flexibility.

[@Donaldjackson83]

U forgot the upgrades lol

[@dinoprather1254]

If you can't do the repair wright,dont lead others wrong !!!

[@WeakestofWeeks]

It's okay to make mistakes.. you even made a mistake using "wright" instead of "right" 😄 The incorrect rear strap replacement has already been resolved but I appreciate the words of encouragement 🤪 kzbin.info/www/bejne/qmnUZpaheL6KpLMsi=H3o9Phu6Yj2qMgEz

[@kurtdussander4944]

U shooten cridisize utters when we’z awl has are own fawlts.

[@alanprice8284]

Be nice

[@danieljurgill1681]

Your video should be removed. You cannot change locations of ground straps willy nilly. Keep the original ground locations , then do another video.

[@WeakestofWeeks]

As long as the original part is properly grounded to metal, it's not an issue. It's not uncommon in the rust belt to have a broken ground stud or rusty connection, so a new connection in a more suitable location must be used. For example, the GMT400 passenger cylinder head to firewall. Many firewall studs shear off, so sometimes theres no alternative but to move the grounding location. As long as it's grounded somewhere to the body, it serves the same functional purpose. However in my case, the rear ground strap was improperly attached and has been addressed and resolved kzbin.info/www/bejne/qmnUZpaheL6KpLM

[@danieljurgill1681]

@WeakestofWeeks I agree ,you can move grounds if the metal is adjacent ,still the same part. The fuel fill neck ,without the ground strap , is isolated via rubber hose connections. The Engine , with rubber motor mounts, is also isolated, and can have a different ground potential than the frame. That is why there is a ground strap between the engine and frame.

[@michaelpepper885]

Why not just use a different flange bolts and why not just go buy already wrapped ground wires you could use any wire as a ground wire they sell them at auto stores. Pretty sure ground wires are blue right. What about all the other grounds? There's one hidden inside the frame by the rear passenger window

[@WeakestofWeeks]

If I were to redo it, I would likely just go with a standard wire with protective casing. Most automotive grounds are black. I wanted to replace mine with the factory style ground straps but didn't think I'd run into the issues I did. I figured it's better to show the struggles I ran into so viewers can decide which way they want to go about replacing theres.

[@michaelpepper885]

"I'm OCD...I can't live with just tge eyelit being wrapped...OK now I have to go back and wrap them all". Lmfao. But seriously, I totally and completely understand. People either love you for this trait, or they hate you. But you know what I've learned? Who gives a rat's ass what everybody else thinks. As long as you're right with the universe and those things are wraps and you can die tomorrow feeling completely fulfilled annoying you gave it 110%. Because if you're not going to go 110 what's the point of doing it at all. But it's crippling sometimes it's so crippling LOL