Troubleshooting 2000 Ford F-250 Fuses and Wiring Harness for 7-Way Trailer Connection

Question:

I have a situation where the left turn/stop/tail circuit for the trailer is not functional. I have a factory 7-way connector at the bumper and a hardwired 7-way in the bed. The bed connection was spliced into the trailer circuits under the bed by the spare. I dont see anything there that would be causing this problem and it exists at both 7-way connectors. In the fuse box, the left turn/stop fuse #1 i believe is blown. When I replace it and activate the left turn signal, it immediately blows. Using a multi-meter I confirmed that the left turn/stop circuit is grounded after the fuse. The question: where do I go from here to find the short? Are there any locations between the rear f the truck and the under hood junction box that I should check for this short? Any help would be great. P.S. is there a t-connector/adapter that I could purchase to connect the existing in-bed plug to the factory bumper plug extension connector gray, square, 10 pins and eliminate the splices? Thank you!

asked by: Chris D

Helpful Expert Reply:

For your 2000 Ford F-250, the fuse location 1 is a 20 amp fuse for turn/hazards in your fuse box. There is also a fuse for trailers that is a 7.5 amp fuse also in location 1 and location 3 of the other fuse box. Anything beyond those fuses will be a possible wiring harness issue and you would need to trace prior to the fuse for short using a circuit tester like # PTW2993. It sounds like you may have a wire that is grounding and blowing that fuse.

For the 2nd wiring harness, you can use the Hopkins Endurance 5th Wheel/Gooseneck 90-Degree Wiring Harness with 7-Pole Plug # HM40157 which has the square gray connectors you mentioned.

expert reply by: Jason S