How to Replace a 5 Pole Flat Wiring Harness That Has 7 Wires

Published 02/13/2020

Question:

I need to replace my plug in only. It is a 5 pole male with 7 wires coming from the trailer . Do you sale this part or have a part # for it.

asked by: Chris F

Expert Reply:

I have a solution for you, but we do not have the exact replacement for this wiring harness. Instead, I recommend using the 5-Pole Flat Connector # A40W5B to replace your old connector and then combine one of the wiring functions on the old harness into one wire on the new harness. You'll want to test the functions of your existing wires but my best guess is that the way this is currently wired your blinkers have individual ground wires and that harness has no reverse light wired in- these would be the two wires I would combine (white with green stripe/white with yellow stripe).

Typically a 5 way differs from a 4 way in that it carries a reverse light circuit; it doesn't appear that harness carries a reverse light circuit (judging by the colors of the wires) but as I mentioned, you will need to test the functions on those wires.

In order to test the wires you'll want to take a battery, connect the ground circuit to the negative battery terminal and then touch each wire to the positive terminal to find out which circuit is activated when it receives power.

expert reply by: Erik B