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Trailer Wiring Color Codes

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Old 03-11-2011, 07:14 PM   #1
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Question Trailer Wiring Color Codes

I have a 2000 Sonoma, and I recently got a cap for it. I have the wiring harness to plug into the cap, but I need to tap the CHMSL wire and a hot wire for the dome light.

I have a trailer wiring harness already installed, but I can't remember which color is which and if anyone here can tell me without me having to test each wire with my multimeter, I would appreciate it.

Also, there is a light-blueish wire inside the framerail next to all the other wires that is looped around and has a tag on it, I think this is the CHMSL wire but the tag is so worn I can't really read what it says.

Anyone know off hand if that is the CHMSL wire, and where I can find a constantly-hot wire for the dome light without running wires all the way up the truck?

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Old 03-11-2011, 07:32 PM   #2
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Re: Trailer Wiring Color Codes

According to my 2000 Jimmy owner's manual, the light blue wire is aux stop lamp. There is not a constant 12v wire, unless you have the 8 wire harness. It is common for people to hook the dome light to the tail light circuit instead of running a new hot wire. You just turn on parking lights to operate dome lamp.
Old 03-11-2011, 07:36 PM   #3
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Re: Trailer Wiring Color Codes

Yeah that's what I was hoping the blue light was, but there isn't a constant 12v for the trailer I guess huh?

Maybe I will run a wire from the front then, maybe I could even get fancy and splice it in with the dome light in the cab?
Old 03-11-2011, 08:55 PM   #4
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Re: Trailer Wiring Color Codes

No constant 12V back there anywhere. I ran a 10 gauge stereo wire up the drivers side frame rail to the 12v positive lug on the fuse box so could put in a cigarette lighter plug as well as hooking up the light in my topper. I wired in a lighted on off switch for the lighter plug and light as well.
Old 03-11-2011, 09:13 PM   #5
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Re: Trailer Wiring Color Codes

that sounds like probably the best route for me, thanks!
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