Truck/Trailer 7-Pin Issues

I had the same error on my Tekonsha P3 whenever I borrowed my friends flatbed. Occasionally, the connection was there and the brakes would work a little, but as soon as you got in to them at all - such as setting the gain with the manual trailer brake lever after loading up the trailer - the brakes would grab once, then throw the error and not work for a while. After chasing wires for a while, cleaning connections, redoing connections, test lighting pins, etc, it turned out that one of wired to one the drum brake actuators (the big electromagnet in the drum) had been torn. Either the magnet before it was still wired in or the other side of the axle, but basically it would ground out through the magnet itself but then quickly over current the line and the brake controller would flip out.

To the OP’s issue - I agree 100% with checking ALL bulbs and test lighting sockets. It also helps to have another set of hands to juggle wires while you test. I’ve found several bad wires that way.

 

Well I do know the trailer brakes work because when I bought it the brake away switch was missing the pin, let alone the wiring under the trailer was all tore to shit. But ibwas able to at least get on acle wired back up and I went to move the trailer and it was locked up. Assuming because the pin was gone. Had to undo the wires and it released the brakes.
Ill check the fuses tomorrow

 

Checkee fuses, all good. Checked connection all clean, no burn marks etc. Trailer has new plug. Guess well see when I move the trailer next week

 

Alright help me out with some advice here. My truck came with the tow package from the dealership. But I'm replacing the wiring harness with a Tekonsha harness. Things aren't quite the plug-n-play I expected.

The Tekonsha harness has this plug, which is the same end as the end that's clearly part of my trucks wiring harness. I figured I'd be plugging into this large plug behind the driver side tail light, but instead this harness seems to bypass that plug.

The tail light plug on my truck connects to another harness, which then connects to my trailer 7-pin socket. So I'm bypassing a lot of wiring harness and plugs by installing this kit. I just want to make sure that's correct. It's the opposite of what I was expecting.

The new wiring harness has this socket on the left, which is the same end (female) as the end attached to my truck as part of it's stock wiring harness.




The male end of what plugs into that female end (the one attached to my truck) is what runs to the 4-pin connector. So by installing the Tekonsha, I'm bypassing the female plug that's part of my factory wiring, and instead plugging into the male end in this photo below.



I thought what I'd be doing is plugging my new harness into the socket on the right in the first photo. Instead I bypass both it, and the circled connections on the right of the last photo. I connect to the plug circled in the second photo.

Does that seem right to people, assuming I did a decent job of explaining things?

Since I'm replacing a dealer-installed harness setup with an aftermarket setup, rather than aftermarket with aftermarket, I'm a little confused on what's happening back here.

 

I will still be working on figuring out everything from the above post. BUT, I did install the new 7-pin socket, and everything on the trailer now works when I connect! It was almost definitely this corroded, broken connection that was hidden inside the conduit that was causing my problems.

 

FWIW, even though I don't understand it, the new wiring harness installed just fine and works. It seems to bypass a bunch of OEM wiring, but since I don't know what's what back there for wiring, what do I know. What's important is that it works.

Clearly works very differently than the dealership-installed towing package wiring, but that's ok.

 

Hooked up to trailer today to pack up and leave and truck recognizes the trailer now so heres to hoping it stays that way