92 K2500 Trailer Brake Controller connection

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I've read that some of our GMT400's came with a factory plug in the harness to plug in a trailer brake controller. I've searched the archives and cannot find what year that might have started. Anyone know if a 92 might have it? I crawled under the dash but could not find such a plug whether that is a 2, 4 or 5 bladed plug. Can not find anything. Would like to find out before order a Prodigy 3 controller with the GMC wiring harness.

My truck is a "Camper Special" and came with the HD weight distribution trailer hitch, dual batteries and trailer plug (but I think it's only the 4 pin plug).

Thanks,
Rich
Maple Valley, WA
 

Erik the Awful

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When I've gone to Pull-A-Part for a rear harness, I looked at later GMT400 Suburbans. They at least have the wires for trailer lights, taped up. They're also 90% less likely to be hacked up like a pickup harness. I don't know about wiring for a brake controller. There are two other wires taped up, but I only needed to hook up a 4-wire plug, so I didn't research.
 

packer0440

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I've read that some of our GMT400's came with a factory plug in the harness to plug in a trailer brake controller. I've searched the archives and cannot find what year that might have started. Anyone know if a 92 might have it? I crawled under the dash but could not find such a plug whether that is a 2, 4 or 5 bladed plug. Can not find anything. Would like to find out before order a Prodigy 3 controller with the GMC wiring harness.

My truck is a "Camper Special" and came with the HD weight distribution trailer hitch, dual batteries and trailer plug (but I think it's only the 4 pin plug).

Thanks,
Rich
Maple Valley, WA
My truck just also happens to have this camper package (same year). It was still necessary to run wires for trailer brakes and the 12V accessory wire, as well as wire up and install a brake controller. The other wires I think are just hanging there in the back (LT, RT, running lights, ground).
 
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My truck just also happens to have this camper package (same year). It was still necessary to run wires for trailer brakes and the 12V accessory wire, as well as wire up and install a brake controller. The other wires I think are just hanging there in the back (LT, RT, running lights, ground).
Thanks for responding because you confirm what I suspected - the convenient plug I want came on later model years. Now I'm wondering if its a DIY or pay a professional. I'm so wary of taking my vehicles anywhere these days - seems it's a crap shoot whether you get anyone knowledgeable and a sure bet, whomever it is, is going to charge a couple hundred dollars just to look at it. Why am I getting so skeptical.
 

packer0440

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Just for kicks, check for the two taped wires as the other reply mentioned; I am actually working on another truck right now (90 K3500) that had two wires taped under the dash that ran all the way to the back of the frame. If they are there, you may be able to use those as your trailer brake wire and 12V accessory, making the hookup much easier. It is not too bad of a job to do with running the wires taken care of. But, nothing wrong with having it done professionally if you know a place that does things right.
 

Supercharged111

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There's no plug, just some taped up wires on the later trucks. I have my doubts as to whether or not they came on a 92. There would be a blue and orange wire taped up near the brake booster and those with a few more at the aft end of the truck.
 
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Rained all day, but hoping tomorrow I can check for those wires. Got a quote to install one (parts & labor) of $495. I think I’ll do it myself.
 
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I crawled all over the truck - under the dash and under the rear plug. I could not find a separate wire that may work for the Brake Controller. The 7 pin plug only has 4 wires going to it. I'll have to run a wire from the Controller to a new 7-pin connector.

Rich
Maple Valley, WA
1992 GMC K2500 454/4L80E/3.73/Camper Special
 

Supercharged111

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I crawled all over the truck - under the dash and under the rear plug. I could not find a separate wire that may work for the Brake Controller. The 7 pin plug only has 4 wires going to it. I'll have to run a wire from the Controller to a new 7-pin connector.

Rich
Maple Valley, WA
1992 GMC K2500 454/4L80E/3.73/Camper Special

If the wires in the back are there, they won't jump out at you. They're bent forward and taped to the harness. They'll be a foot or 2 from the bumper.
 
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