How to Determine Functions of Trailer Wiring for 7-Way

Question:

so im replacing my trailer end with a new plug in. the old one had colors wire red went to black, green to brown, black to blue, white to white, yellow to red, brown to green. well the new plug does not have the colors just TM for taillight LT left turn RT right turn AX auxiliary and so on. not sure how to hook it up???

asked by: Monty S

Expert Reply:

When installing a new 7-way trailer plug like the 7-Way Molded Trailer Wire Connector # H20043 the only way to determine the wiring connections is by testing the functions of your trailer wiring.

To do that you will need a standard 12 volt battery and jumper wire with # 10-1-1. Simply touch one end of the jumper wire to the positive post of the battery and then touch the other end to different wires to see what circuits illuminate.

expert reply by: Kyle S