# Where's the warning light wire in a 2500HD



## Chris-R (Jul 9, 2005)

I'm ready to install a permanent warning light on top of my back rack. I want to connect the light to the dash mounted OEM warning light switch and understand that there's already a wire somewhere above the headliner. I'd rather not disassemble any more of the headliner than I have to so can someone tell me where I might find the wire for the warning light? I have an 05 GMC 2500HD extended cab. Thanks for your help.


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## Plowfast9957 (Feb 14, 2005)

Hey chris I just did mine. If you pull down the headliner in the drivers side its right there taped to the roof. about 6 feet of wire coiled up.


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## flykelley (Dec 29, 2003)

Chris-R said:


> I'm ready to install a permanent warning light on top of my back rack. I want to connect the light to the dash mounted OEM warning light switch and understand that there's already a wire somewhere above the headliner. I'd rather not disassemble any more of the headliner than I have to so can someone tell me where I might find the wire for the warning light? I have an 05 GMC 2500HD extended cab. Thanks for your help.


Chris Remove the plastic cap over the upper latch on the drivers side, Gently pull the headliner down in the middle of the drivers side. It should be held with a magnet and velcro. The wire is taped to the underside of the roof with blue tape.

Good Luck Mike


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## sonjaab (Jul 29, 2001)

BTW..............You will be looking for a heavy Brown+
and a heavy Black- wire...................geo


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## Chris-R (Jul 9, 2005)

Thanks guys. It was right where you said it would be complete with blue tape and all. After finding the wire, I ran into a problem. When I pressed the button on the dash, I couldn't get power. After taking apart half the truck, finding the relay behind the back seat and behind the seat belt mechanism, finding no power to the relay, I found a connector near the emergency brake had become disconnected. The bad part is that I had already pulled the switch from the dash, etc. and I blew a few fuses when trying to troubleshoot. Now I dont have instrument lights and I don't have the little power-on light when I press the emergency light switch but I have everything else including transmission settings, radio, etc. I can't seem to locate a fuse for the instrument lights even after looking at the book and pulling and testing a bunch of fuses in the engine compartment and on the dash side fuse block. Does anyone know if there's a dedicated fuse for the instrument lights?


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## sonjaab (Jul 29, 2001)

Chris......

I forgot to mention the relay was in the left rear B pillar by 
the upper seatbelt anchor.

Go here for complete VYU plow prep. info."
http://www.gmupfitter.com Go to publications pg. 27


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## PerfiCut L&L (Oct 18, 2005)

Im confused as what switch your talking about? I didnt know their was a "pre-wired" warding light switch. Can you explain what switch this is and where its located?


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## flykelley (Dec 29, 2003)

sonjaab said:


> Chris......
> 
> I forgot to mention the relay was in the left rear B pillar by
> the upper seatbelt anchor.
> ...


George
I didn't have to do anything to my relay, it was already hot. Thats kinda wierd.

Regards Mike


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## wgsshowe (Nov 18, 2004)

PerfiCut L&L said:


> Im confused as what switch your talking about? I didnt know their was a "pre-wired" warding light switch. Can you explain what switch this is and where its located?


The snow plow prep package for 2500 HD GMC comes with a prewired push button switch with indicator light right by the passenger air bag disconnect switch. The wires for this light are termintated in the headliner above the drivers side.


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## Antnee77 (Oct 25, 2005)

Heres the PDF file for trucks with a snow plow prep package: http://www.gmupfitter.com/publicat/2003_BB/LD_Special_Applications.pdf


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## golden arches (Oct 30, 2003)

I've been looking for this silly thing for 4 years! Even the local dealer didn't know where it was. 

The diagram indicates it's in the center column.. on ext cab's is it in the front pillar or ? 

thanks all!


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## golden arches (Oct 30, 2003)

golden arches said:


> I've been looking for this silly thing for 4 years! Even the local dealer didn't know where it was.
> 
> The diagram indicates it's in the center column.. on ext cab's is it in the front pillar or ?
> 
> thanks all!


Hey guys, went out, pulled the seat belt cover and headliner and there it was!

It's hooked up and running.. thanks for your insight.


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## csx5197 (Sep 26, 2006)

Does anyone have some pictures of this? I've been trying to find it for awhile now and with Plowing season just around the corner, I'd like to find it. I found what I thought was the wire, but was too afraid to just pull the wire and hope it was it.


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## B&B (Nov 4, 2006)

csx5197;602510 said:


> I found what I thought was the wire, but was too afraid to just pull the wire and hope it was it.


 Should have been two wires, a brown and a black together. If so, then they're the corrrect ones.


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## 042500hd (Oct 10, 2004)

Nobody could tell me what that button did at 2 GMC dealers. Everyone thought it was for a trailer brake. It's also no where in the manual that I could find.


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## csx5197 (Sep 26, 2006)

B&B, thanks, It might have been, if I recall it was a thick black wire. Just was hoping someone might have had a picture of it, so I could be certain, it might have been two wires.


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## 042500hd (Oct 10, 2004)

If anyone has a pic of how they used that wire I'd like to see it. I don't want to drill a hole in the roof, was thinking of maybe getting the wire out near the cab brake light. Any thoughts?


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## B&B (Nov 4, 2006)

042500hd;603631 said:


> I don't want to drill a hole in the roof, was thinking of maybe getting the wire out near the cab brake light. Any thoughts?


Thats the way many guys do it. On many trucks it's actually doable to just remove the third brake light assembly and go in through there. I've fished them out with a coat hanger to grab them before...no need to even pull the interior apart. Drill a small hole in the brake light lens and run the wires out through it along with a dab of silicone.


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## mckaloz1 (Jan 23, 2009)

*Roof Beacon light*

have a 2003 2500HD with plow prep package. Found the wires in the headliner and pulled them down so I can hook up a light bar. No power to either wire. replaced fuse in underhood fuse panel just to be sure. still no power. I know where the relay is in the back d side c or b post. haven't checked that yet because pain in the butt to get to. I've heard something about some disconnected wires near the emergency brake. Any ideas? Have tried flip-flopping wires with and without the OEM switch on and off. Light on switch comes on correctly. Have checked the upfitter page as well and everything seems the way it should be. Have also tried it with my plow hooked up and unhooked. Thanks. Mike


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