Chevy Trailer wiring harness
 

I bought a used 2010 Chevy Silverado Crew a couple months back. We picked the boat up in mid May and towed it to the lake and due to weather and moving hadn't had a time to use it till this last week. What I found when I tried to back up was that the lock out solenoid wasn't engaging and the brakes would lock up. Luckily I had the emergency key thing and just used that so we were able to launch and use the boat. I didn't have the right tools at the lake so had to wait till we got home yesterday to look at it. The truck appears to have a after market harness, but I'm not 100% sure as I bought it used. Guessing that because my brothers new 13 with factory tow just has the 7 round and mine has a 7 round with a 4 flat on the side. When I tested it at the truck side plug I have running lights, brake lights, turn signals, but no power on the reverse lock out/light pin. Looking at the plug(on the truck) I believe that should be the lower left pin/spade. I came to that conclusion as thats the only pin/spade in the trailer side plug I don't account for with running, left turn, right turn, brake. Also am I correct the center is the ground?

I guess the question is should a standard plug be wired for the reverse light pin? Or is this something I have to add? Can I just pull a tail light and tie into the reverse light and run it to the correct pin?

It should be the blue wire and it should be in the plug.. Are you using a round or blade plug..

A little trick that works is, take the blade plug and turn it over and plug it in.. Now the 5th pin (brake solenoid) is now powered but the running lights ( first male pin).. Just turn your head lights on and the 12 volt power will release the brakes..

Yeah I wish it was the 5 flat, I know that trick! Unfortunately my boat mate trailer came with the 7 round and thats what I am having issue with.

Does any one know the colors coming off the back of the plug truck side? Specifically for the lockout/reverse wire?

I had the same problem. Check the fuse under the hood. I can't remember which one, but a search on dieselplace.com will tell you. I had the fuse pop when I backed into the water a little too far.

Definitely check the fuse, I've had three different chevys hooked to my boat and they all had a blown fuse.

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I will have to check them. Wouldn't the fuse blown wipe out the whole plug? I have everything except the backup lights. Turns out that the center pin is the wire in question. The spade/pin I thought it was is the ground.

Sure enough fuse #10 trl BK lights was blown. Can't test it until the morning as my wife is at work, but sure looks like a winner. Thanks guys.