Intermittent problem. Driving down the road and for no reason the trailer brake disconnect warning comes on but nothing is hooked up to it. This is accompanied by the engine warning light, traction control light, service 4wd light, etc. The truck stops going into 6th gear. No miss and the engine feels like it's still running fine. I put a code reader on it and erase the codes, runs fine. I've tried taking out the fuse for the trailer brake system but it didn't fix the problem. Also having intermittent issue where the brake lights stay on while driving. It gives every appearance of a short, anyone else have this issue and can tell me where to start looking?

 

I'd start with the trailer plug. On the back side of the 7 pin it should have a plug into the main harness, disconnect here, inspect for corrosion, then try using the pickup like normal without it hooked up and see what it does.

I've replaced alot of the trailer plugs that even looked ok over the years on 3rd and 4th gen trucks for brake light/trailer brake issues. Your other warning light issues seem like something more involved then I've seen caused by the plug, but you could have multiple things going wrong.

Speaking of which my 14 I have now will quite often say check trailer brake after driving in the rain or carwash without a trailler connected, sometimes i randomly get a trailer disconnected ding. I should replace mine as well.