Troubleshooting # 118426 T-One Trailer Wiring Harness Installed on 2004 Ford Truck

Question:

I had a mechanic hook this up for me and it all tests good until its connected to boat then u get nothing. U can take both male and female almost all the way together its hot but once they r fully connected u get nothing. We tried another vehicle and it works fine. We also cut the male plug off vehicle and tried that it does the same. Help please

asked by: Shirley L

Expert Reply:

Good thinking trying the boat on another vehicle, that's a simple way to troubleshoot that most folks don't think about. You've pretty effectively ruled out the boat as being the problem.

I'd begin by relocating the point where the white wire with the ring terminal from the converter box attaches to the vehicle. Make sure you're connecting to clean, bare metal with no undercoat or corrosion. If you've grounded the circuit to the chassis (instead of the frame) putting the ground screw through a seam where two panels overlap works best because the metal's thickest at that point.

Just to be sure, check the ground point on the trailer tongue and ensure it's secure and not corroded. Please check these connections. If this isn't the problem, please get back with me and we'll look at some other less likely possibilities.

I'll link you to our trailer wiring troubleshooting FAQ.

expert reply by: Mike L