Chevy GMC upfitter AUX switch 5 wire location and Third Brake Light Removal 2020 2021 2500 3500

[@Ben-rz5wl]

I just recieved the Magnum rack I ordered and plan on having a strobe in the middle top running off that #5. I'm shaking my head at the thought of tearing apart my brand new AT4 2500. Thank you for the videos, they are a huge help.

[@jeremywhittington7605]

The number five switch is the green wire that’s integrated in the harness coming from the aux fuse box underneath the kick panel on the driver side… it’s meant for those trucks equipped with a roof light. I just pulled the pin out of the harness plug end, removed the wire, and used it for whatever I want.

[@JebClarke902]

I know this is an old comment, but how did you pull the pin out of the connector? I have been struggling for an hour with no success. I really would prefer not to cut the wire, but I can't figure out how to release the pin from the connector.

[@Hutchy45445]

Great video guys! I’ve watched many videos on these aux switch installs and noone found out what that was for

[@Mike44460]

Thinking out loud. I have made comments about having to pull the transmission on the Dmax 3.0 for the oil pump belt. I thought that was insane, but this takes the cake and leaves no crumbs. On the 2011 2500HD I just traded in for a 2021 2500 HD High Country I only had two screws and one 8mm bolt and the knee bolster was off. With this design you have to dissemble half of the damn dash to put install the switch for the whirly gig light on the roof and then almost half of the head liner to get to the nuts that hold CHMSL assembly where the wire is you need for the roof light. If you ordered the snow plow option with the intent to use it just add another $1,000.00 for the dealer to tackle the two issues here and then there is the device that stops the dash for going blank when you operate the plow. I'll bet that once someone jumps through the hoops here to plow snow, this will be their last GM product. Remember what Mrs. Gump said about stupid.

[@snowcatcowboy]

Completely agree, we upfitted our 2013 Chevy 3500HD and it was somewhat straight forward; this 2024 3500HD is the biggest PITA I have ever come across

[@Mike44460]

@@snowcatcowboy Engineers............

[@dank2101]

The wire location is noted in GM UI Bulletin #157b

[@mattman6161]

this is exactly the info everyone needs. remove rear tail light or with spoiler just drill a hole and fish the loose wire out. easy shit

[@curteous1]

Great video, very informative regarding the elusive aux 5 wire location as well as how to get to it, thank you brother!

[@rebelliners]

Glad it was helpful!

[@trevor6125-z7g]

Thanks for sharing this! Worked for a 2021 GMC Sierra 3500HD.

[@rebelliners]

Glad it helped

[@apulbroo]

This is exactly what I was looking for! Great job

[@grumpy1311]

Great to know!! The question is will the extruding wires cause water ingress to the taillight?? Have seen that as issue in past GM year trucks. I have '24 3500HD w/o the silly rear spoiler to deal w, just the brake light . The 4 wires under dash are the same color config and i assume same switch #s.

[@cazzac7958]

Geez! First let me start off with I have a 2021 2500, but hats off to ford. The aux wiring is all under the hood next to the fuse box. Easy as pie wire up all attachments

[@rebelliners]

Yeah I am a Chevy man but you are correct. All the manufactures have their pros and cons for fun search how you check the transmission fluid in them new Ford Super Duty's.

[@markmanning5683]

From experience here. Many Silverado's will experience the Rear Window leaking slightly. Where you are with the Spoiler off, put a full length of painters tape along the plastic piece of the top of the window, then fill that trough at the top of the window with silicone, fill it to the top edge, wait a couple hours for the silicone to start to cure (full cure in 2 hrs.). take the painters tape off. Done. Again by experience, the Two Alignment Yellow Push Pins. From the inside use a 7 or 8mm long socket and push from the inside of the Truck Cab Up along this Alignment pin and pull the spoiler away to ease removal. You could even use a pair of Bent Needle Nose Plyers to squeeze the Alignment Pins as you pull the spoiler away. Lastly, it would be a benefit when putting the spoiler back on, put a good size dab of silicone at the top and bottom of all these bolts to help make sure water does not come in. If you look closely the bolts removed have a flimsy rubber grommet around them, either replace with new grommets or use the silicone. Have fun and be sure to reconnect that 3rd Brake light on the Drivers Rear Hood liner. Easy to forget that. 20 plus years of Upfitter experience on Public Safety Vehicles. Whelen, Federal Signal and Sound Off, Code 3, Havis Shield and too many Motorola radios and computers to mention.

[@vinceferraccioli4661]

Hope you put some sealer around the holes.

[@k.b.322]

What holes? The existing holes that didn't have sealer to begin with?

[@vinceferraccioli4661]

@k.b.322 Page 6 August, 2020 Bulletin No.: 18-NA-383 5201861 Important: The 8 central roof spoiler nuts are NOT reusable fasteners. The original fasteners must be discarded and replaced. That's why I use butyl sealer.

[@rebelliners]

Yes We use SEALING PUTTY www.amazon.com/Stero-Manufacturing-Company-P571878-SEALING/dp/B00J47UJ60

[@vinceferraccioli4661]

Ya, it's called butyl sealer. Have been using it for 40 years. Best thing ever

[@vinceferraccioli4661]

@k.b.322 yes it did have sealer lol

[@at5252008]

This was a great video installed my strobe today

[@rebelliners]

Glad it helped

[@MarkIrwin-mz8jd]

Its a extra wire when the plow prep package option is added

[@travelinmillwright9769]

So I'm terribly lazy. About where is that wire loop set in relation to the light? I'm going to just drill the fiberglass and put in a rubber plug when I'm done.

[@snowcatcowboy]

Great video! Thanks! I have a 2024 3500HD LT and want to add the 3rd Brake Light Camera; (box bed camera) did you see any extra wires for the camera or are the in the light plug since the camera is formed into the brake light?

[@GaryLX870D]

Nicely done,,, I wish mine had that.

[@zrtdave]

Mine has it but there’s no way in gods green earth I’m doing all that just to use factory run wiring, Completely insane… great idea, but they forgot to revisit it before final production… duh!!!

[@Hutchy45445]

Odds are your truck does have it. I don’t think you have to tear all this apart, like he does in the video; he’s just chasing the wire to see where it is routed (suspecting it was deadened in the loom somewhere)

[@zrtdave]

@@Hutchy45445 maybe I’ll have a look see!

[@donaldhudson4948]

SPENT TWO DAYS LOOKING BUT I FOUND THE ROOF LIGHT WIRE UNDER THE GLOVE BOX BEHIND THE RIGHT FUSE PANEL . HARNESS THEN GOES UP THE RIGHT FRONT A-PILLAR

[@rebelliners]

What color any photos

[@bobz1962]

Is the wire easily identifiable? Do. you have any photos of it?

[@ericmagnaye]

This might be a long shot, looking at the timeline this video was posted on, but I have a quick question. I installed an aux switch for 404part. I was able to locate the fifth cable, but on my 2022 GMC Sierra 1500, the cable has no power. I need help determining why.

[@rebelliners]

What cable is powerless?

[@ericmagnaye]

@@rebelliners the one at the fiberglass spoiler. The black and the other wire. Yours is green with a tracers. My is purple in color.

[@rebelliners]

@@ericmagnaye more than likely left side dashboard underneath not connected

[@ericmagnaye]

@@rebelliners thank you for you help, do you have more context on it?

[@rebelliners]

@@ericmagnaye I believe the wire would just need to be powered by a source or try local dealership maybe a kit that can b connected like this video if you have located it

[@kylecherry3156]

Sorry I’m 7 months late lol but you should do a video on making the tail lights strobe. According to knapheide and i confirmed via knapheide, those tail lights are prewired and for strobes. There are factory integrated amber strobes in the clear portion of the tail light. I have the same truck, with the same bed, I’m just not brave enough to start throwing 12 volts to wires that I’m not 100% sure what they do. I’ve wired plenty of my older trucks with strobes, but this new stuff is confusing

[@rebelliners]

Well that's a new one think someone is pulling your chain but if you got more information we are all ears.

[@christopherjohnpaul5591]

@@rebelliners Kyle is right. The clear portion of those taillights has amber strobes in them along with the reverse light. I just received my 2022 Silverado 2500HD from my boss. I hopped in the truck and Aux 1 switch was labeled “Strobes” It’s butt spliced in the cab by the Aux switch fuse box. It doesn’t power up with key switch off and also when the reverse lights are activated. I plant to tie-in a couple strobes and mount them on the front end somewhere. I’ve only had the truck a week and I got plans. I’m adding an aux battery and an inverter eventually. I like the truck, I just wish it was a Sierra instead. The front end looks so much nicer on the GMC. I’m going to complain, I didn’t pay for it.

[@rebelliners]

@@christopherjohnpaul5591 Can you email me a pic of where they taped that I have not had time to look at one yet. [e-mail]

[@nwmi493]

vehicle engineers are a special breed. They aren't very forthcoming with specifics. What are you doing about the empty plug for the tailgate that is left open when the tailgate is remove for adding a sander? Our dealer cant find a blank plug to close it up..

[@bobz1962]

Great video!

[@AFTERMATHRC]

So where does that wire go up? Is it going up through the A-Pilar on drivers side? I’m just asking because I want to utilize it for led light bar on the front? Thanks awesome video.

[@rebelliners]

best of my findings it in the rear driver pillar

[@timsage7476]

Hey Nat, just watching this video, for the Red 2021 Chevy 2500HD, where You found that the wiring was already hooked up to the factory installed upfitter switches. Just wondering if You have ran across any others that GM had already installed the wiring? I have a 2022 2500HD on order, and ordered it with the upfitter switches installed from the factory, so was just curious if I would have to install the wiring or if GM was now doing that in production!

[@rebelliners]

Good question I have seen 4 connected from gm and 4 not all 8 owners said the truck was to come with factory installed upfitter switches keep me posted

[@timsage7476]

@@rebelliners Okay I will! I will let You know if mine comes in with the switch wiring installed or if I just find all the parts laying in the cab and I have yo install it myself! LOL

[@timsage7476]

I hope mine comes in all hooked up, for as long as I have been waiting, I ordered it back on July 2nd 2021, it is in event code 3000 with a build date on Jan. 24th 2022!!! I originally ordered a 2021, but it got moved to a 2022 back in Sept.

[@204farmer]

Does switch 5 (or the rest for that matter) remember position after cycling the key? Our truck came with the harness but no panel or switches so I'd like to confirm before buying the parts. Beacon needs to be on by default (or memory) and turned off for occasional road use

[@k.b.322]

Yes they do, fortunately!

[@riesspellegrino1806]

The wire is there even if your truck didn’t come oem with the unfitted switches

[@rebelliners]

I find that offen with police car builds wires are all still their they just go to nothing must be simpler to just use the same harness

[@simpleman4196]

Thanks a lot for this video. Pretty stupid how much of the truck you have to take apart for that.

[@gohangan]

Is it possible to use the brake controller wires for something else?? My 2500 HD came with a brake controller attached to the switches by the head unit. So, I’m wondering if I can repurpose those 3 wires

[@rebelliners]

I would test them to confirm what they do

[@MrJoe8K]

Cool, now to bad he didn’t put a waterproof quick disconnect incase the owner ever wanted to easily get a bigger bar.

[@alekpelton3592]

I have a 2022 single cab gmc and I can’t locate the plug that sends power to the AUX5 function.

[@rebelliners]

Try the driver side corner inside cab u should find a plug

[@at5252008]

How did you handle resealing the weather stripping and waterproofing around the wires?

[@rebelliners]

Made by Neer Called duct seal compound

[@JamesNelson-nn4qz]

What color was that wire?

[@rebelliners]

@@JamesNelson-nn4qz like a green with blue stripe

[@99959bill]

Are the AUX lines 1234 fused or do fuses have to be added?? I want to add this switch panel to a 2020 HD High Country,,, I am told it will just plug in to sockets already there,, why this truck did not have that I could not tell ya,,,,,, So,,, are the lines 1234 fused on the truck or do fuses have to be added??? Thanks.....

[@rebelliners]

Should allready be there

[@rebelliners]

I have seen them set up from the dealer I and I have seen them in a bag under the back seat hit and miss if you have the kit from dealer it will have everything you need

[@99959bill]

@@rebelliners Early 2020 NOPE! So it looks like I need that whole plastic part with the square hole to snap the assembly into and the center of the dash has to come apart also to get that part swapped,,,, what a PIA - eh !!! Notice - no room to add 2 way radios etc.... in this truck,,, but a nice spot just in front of the sun-roof for switches - I think Ford puts 6 there......

[@99959bill]

Thanks!!!

[@lazarogonzalez1333]

I had a question I did everything like the video but none of the wires work when I check them

[@rebelliners]

I get a lot of phone calls on this its typically that strange connector under the dash that you hook up from Gm the plug that runs to the main fuse box under the hood can be tricky to to plug in correctly

[@Arcade-fix]

Aren't you supposed to be able to drill a hole in the spoiler and hook the wire?

[@rebelliners]

U can but good luck I sont like how u would have to reseal it