How to Test the Functions of Trailer Tail Light Circuits

Question:

How do you test the function of the wiring on your trailer? What tools are needed?

asked by: Sandie S

Expert Reply:

The easiest way to test the functions of the taillight wiring on a trailer is to use a jumper wire. You will touch one end of the jumper wire to the positive post of a 12 volt vehicle battery and then touch the other end of the wire to all of the different wires to see what circuits illuminate.

The other option would be to trace the wires back to see where they terminate.

expert reply by: Jameson C