Troubleshooting Trailer Wiring In A 1997 Ford F-350

Question:

I have a 97 f350 and when I have anything plugged into the trailer plug either 4pin or 7pin the turn signals on the truck both flash as if the hazards are on when using either turn signal. Also the trailer lights wont work. Ive tested the trailer lights on another vehicle and they work fine. It appears a previous owner had a trailer brake installed but had taken it out again. I guess Im just asking for tips to look at to try and get them writing correctly. Any help would be greatly welcomed. Thank in advance. Also Im trying to figure out what this is in the picture

asked by: Erin R

Expert Reply:

The wiring in the picture could be the adapter for your brake controller wiring but to know for sure you'll need to trace the wires. Given the age of the vehicle the wiring could be damaged or pinched somewhere causing the issues you're having.

The best and easiest option would be to install the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Item # 118316. This connector plugs into your vehicle's wiring harness, which is located beneath your vehicle, along the driver's-side frame rail.

You'll then connect this into the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat # ETBC7. This can be wired with the black wire running to the battery with a circuit breaker installed in-line and the blue wire running to the brake controller of your choosing. I recommend the Tekonsha Voyager Trailer Brake Controller # 39510 with the Brake Control Plug-In Harness for Tekonsha # 20127.

I also recommend using some Dielectric Grease Item # 11755 for your 4-pole and 7-way connections to increase the reliability and the life of the connection by preventing corrosion and sealing the connection.

I've included videos for these products to help with installation. If you have any other questions please feel free to reply back.