Old Trailer Wiring 5-Way had 6 Wires But New 5-Way Has 5 Wires

Updated 05/05/2020 | Published 07/06/2014

Question:

I am trying to replace a 5 pin harness/plug part on my EZ trailer. I got an appropriate 5-pin plug for the trailer side actually the kit came with both sidesHopkins brand. When I looked at my trailer wiring plug, I noticed that there were 6 wiresthere was an additional white while stuck with the wire set. The ground wire was a little larger and separate. I did not know how to reconcile the extra wire that is already on the trailer side, so I couldnt proceed. Could you recommend how I can get this plug replaced? Where do I hook up the extra wire? I just ended up reconnecting the wires that I had cut.

asked by: Anthony K

Helpful Expert Reply:

The trailer connector that you had is what is called a wishbone harness. It has 2 running light wires so you do not have to run a jumper wire for running lights from one side of the trailer to the other. Harness # A40W5B is an example of a wishbone 5-Way.

All you have to do is connect the 2 running light wires from the trailer wiring together and then to the brown wire on the new harness. Or, if you are replacing all the wiring, you would run a jumper wire from one side of the trailer to the other by just splicing into the single running light wire at some point on that brown wire.

expert reply by: Michael H

Randall R.

5/2/2020

I have a Westbar flat 5 trailer connector that has 7 wires coming out of it... all I can find is 6 wire replacement connectors.Will the 6 wire work? Do they still make the one with 7 wires?

Chris R.

5/5/2020

We do not have any 5-Way harnesses that utilize 7 wires. Most likely your particular trailer just uses an extra ground wire (but I would still test/check to be sure). What you can do is use a wishbone 5-Way harness like # W002290 (6 wires) and simply splice in that 7th wire to the correct circuit on the new 5-Way once you verify its function.