Testing 4-Pole Vehicle Socket to Confirm Wiring Configuration

Question:

I recently purchased a tow behind vehicle prewired with Pollak female 4 pole connector. Your Pollak picture looks like the ground pole is in a different location than the one on the vehicle. If so, does that matter? Or, would I need to change locations of the wiring?

asked by: Larry M

Expert Reply:

On the Pollak Heavy-Duty 4-Pole Round Pin Trailer Wiring Connector # PK11402 the ground pole (shown in the linked photo) is at lower-left. It is certainly possible that your vehicle socket, one like # PK11404, was wired with ground on a different pin. You will need to test the vehicle wiring to confirm so that you can wire connector # PK11402 to match. This is easy to do; all you need is some wire like # 10-1-1 to connect the battery to the contacts on the vehicle's socket. This will show which pin/wire activates each of the functions.

Connect battery ground to the pin for the wire that connects to the chassis or frame. Typically this is a white wire but there is no guarantee a white wire was used to make the ground connection so you may need to trace the wires from the socket to find the one that serves as ground. Then apply +12V to the other pins, one at a time, to see what function goes active, either left stop/turn lights, right stop/turn lights or running lights. Usually the left stop/turn circuit will use a yellow wire, the right stop/turn will use a green wire and the running light circuit will use a brown wire.

expert reply by: Adam R