Troubleshooting Brake Lights not Working on a Trailer Towed by a 1992 Toyota Tacoma

Question:

I am not getting power to trailer connector brake light on my 1992 toyota Tacoma pickup. All lights on truck work fine. On trailer all lights except brake lights are working. Is there a way of testing the convertor? Or, how to test for break power coming in to the convertor?

asked by: Abe O

Expert Reply:

Yes, there is a way to test the converter box of the T-One Wiring Harness # 118379. Basically you need to use a circuit tester like our part # PTW2993 and test for voltage on the input side of the box. If there is voltage there and then there is no voltage on the output side of the converter box you know that the problem is internal to the box.

Before you would replace the box you would want to fix the short that is on your trailer. Otherwise the new converter box would short out as well. I attached an FAQ article on troubleshooting wiring installs for you to check out also.

If the converter seems to work fine I would next make sure that the grounds on your light assemblies are connected to a clean metal surface. The brake light feature of a trailer light draws the most amperage so if there were to be a ground problem it would show up with the brake signal.

expert reply by: Jameson C