How to Test Converter Box of Trailer Wiring to Determine if Theres a Short

Question:

Dealer installed harness and hitch worked for over 20 years on both 1978 Toyota and 1998 Toyota Tacoma. Recently stopped working. Read through r trouble shooting information. Checked out trailer for shorts hooked up battery charger and voltage makes it to and lights dual lamp bulb on both sides. So trailer wiring checks out. I have voltage and tail light works on both sides of boat. I do not have voltage and turn signal and brakes do not work. I suspect the converter is bad but wanted to be sure. I dont see where there is any external voltage running to the converter so believe voltage is from the T1 connector. Thoughts on whether converter is bad?

asked by: Charles

Expert Reply:

What you described can sometimes be due to the converter box shorting out. What you will want to do is test the wires going into the box of the converter box for voltage with a circuit tester like the # PTW2993 to see if there is voltage going into the box when the taillight functions of your vehicle are applied, and then test the output side of the box to see if the current is making it through the converter. If not then the problem is that the converter box has shorted itself out and would need to be replaced.

Before you replace it you will want to inspect the wiring of your trailer to see if you can find anything that would cause the box to short out like corrosion or cut/exposed wiring. These boxes don't usually go out unless there is a short on the trailer that takes it out.

expert reply by: Jameson C