Power at the trailer plug

[dington]

Originally Posted by Blazonic

Did you ever figure out what the problem was? I was checking my wiring the other day and mine doesn't seem to be working either... I have hooked the wire to the stud and the stud has power (fuse is in and not blown) and still have yet to get power to the 12V pin on the bumper connector

Yes, went to the dealer and felt like a dumb ass. The wire I hooked up that said 12 volt trailer feed was actually for aftermarket trailer brakes. The wire you need is on the other side of the fuse box. Its taped down there like the first one but hard to find. The tech knew right where to look . Mine work now. Why the hell didn't they do that at the factory. Hope that helps.

[Blazonic]

Sheesh... I have the factory installed brake controller which already had one Red with Black tracer hooked the bigger stud. I seen the other Red with black tracer labeled Aftermarket trailer feed. I thought this was the 12 volt trailer feed... Well after I just read your post I went out and looked and there was a THIRD red with black tracer wire taped up by the steering column. It has a smaller diameter hole which only fits smaller stud. I haven't tested it yet but I have a feeling that was the problem... Thanks Guys


WHY THE HECK isn't it hooked up from the FACTORY if there is going to be THREE of the same wire

[DuraDawg]

Interesting thread. Sounds like you guys are on to something that may help me. My wife was complaining, that on our 2008 2500HD, that the interior lights on her horse trailer weren't working. At first she thought she had a bad connection, when I looked at the plastic cover for the plug, I noticed the factory pinout description is embossed on it, hard to see though because it's all black on black. Unfortunately, the pins on her trailer are in reverse order for brakes and overhead lights. Obviously, Chevy meant it to be this way, so does the trailer manufacturer have it wrong? Or, do I need to look into finding the this secondary taped down 12 volt trailer feed you all are talking about, and connect it? Thanks in advance for your help.

[Len Todd]

I spent several hours on this problem to and from Alaska. There are 3 Red/Black wires. The one taped up between the Engine and under-hood fuse box is the one that feeds the Aux Power to the rear bumper. The Trailer Brake's Red/Black wire should have already been hooked up to the stud closest to the engine, on the front of the fuse-box. The Third Red/Black wire, located between the fender and fuse-box, feeds the harness that you have to plug in under the front of the cargo box for Campers and 5ers.

I took the truck into a dealer on the way back from Alaska and they could not figure it out. Then I noticed that Red/Black wire at the rear bumper was heavier than the one I had hooked up. That was the tip off to me that there had to be another Red/Black wire someplace. Mine was taped up to the harness between the Engine and fuse-box. But, it was actually located under the fuse-box.

Both fuses for the two studs were already installed, I assume by the factory.

[Hook'em_Horns!]

Originally Posted by DuraDawg

the interior lights on her horse trailer weren't working.

Open the rear 7-pin plug cover on your HD, the pin at 1 o’clock will be the hot 12v aux feed and the pin at 7 o’clock will be the ground. Check for output there first, to rule out a problem with your trailer’s lights/wiring.

If no output (it should be live with no ignition key turned on), proceed to the under hood fuse box area and search for the HEAVY aux wire to hook to STUD #1 on the fuse box.

[bigfish_Oh]

I used my '08 for 9000 miles and did not know the charge wire was not hooked. I asked the dealer about it when I picked up my'09 and he did not have a clue what I was talking about. I got home and hooked it up.

[DuraDawg]

Thanks for your reply, it further validates the issue we discovered.

There's certainly plenty of CYA between the factory and dealers. My wife has unwittingly been pulling her horse trailer without trailer brakes engaged, because of this. The only thing that tipped us off, was when we towed a friend's trailer, and the overhead brake lights did not come on. Since the 2500HD has such superior towing ability, you would never sense that the trailer brake controller was not connected. Oh well.

I guess since they (GM) don't know what their customers will be hauling, they don't bother expanding on this feature. I found one sentence buried in the handbook, back in in 4-5x.

[Len Todd]

My Trailer Brake wire came hooked up from the OEM. What does not come hooked up are the Aux Power wires to the Trailer Harness. They even had the fuses in on the Trailer Brake and Aux Power. They just did not connect Aux Power. If you have the Integrated Brake Controller, it should have been hooked up.

[bigfish_Oh]

please clarify, I was assuming this extra wire that I hooked up is the hot wire to charge the trailer battery for when your trailer unhooks and pulls manual brake pin to engage brakes??

[DuraDawg]

According to one of our local dealers' service foremen. Some trailers have surge type, others electric. In our case electric, which means the wire needs to be connected in order for the controller in the trailer to engage it's braking system. Bottom line, is the factory (Chevy) doesn't make the connection. You have to do it yourself, or have it done. The HD harness assembly has it, just not connected. Please refer to the 2008 Silverado Owner Manual, section 4 page 85, and section 4 page 87.