Trying to figure out where to start looking.
A couple weeks ago my 7 way connector on the trailer broke (old plastic just cracked) and all the wires pulled out. I was able to get a replacement and connected everything up and it looked to be working correctly - but I was just checking everything with the truck not fully connected - only the plug in - hitch not sitting on ball.
Everything checked out - brakes, blinkers, running lights - with not sitting on ball.
Before leaving and fully hooked up - brakes and blinkers worked no issue, and it was daylights so didn’t check running lights.
On the way home, once the sun went down, we realized the running lights where not working. We checked the connector (since we had just replaced it) and everything looked good. Used a multimeter to check and everything seemed good.
Checked the truck and found a blown fuse for the running lights. Replaced fuse. Running lights working again with trailer connected, but not sitting on hitch. Once lowered down to hitch, fuse blows again. I did notice we had an error message on brake controller when only connected via wiring but message went away when connected fully through hitch.
Where should I start looking? I assume it is a grounding issue, but all the wiring is ran through the trailer frame so I am not sure where to look there. Anyone seen this and know where they found the issue? Thanks for the help!