Adapter for 7-Pin Harness on Vehicle to 4-Flat Harness on Trailer

Question:

I simply want to wire my trailers 4-wires to a 7 way connector for use with my trucks 7 way input as the 4 way flat connectors do not last long and often become bent and worn out in less than 2 years.I would prefer to use the more durable round 7 way connector but most diagrams outline use of all 7 wires my triler does not utilize anyway so can I simply connect the 4 wires I need to 4 of the screws on the 7 way connector. I see 3 of the wire colours to use on the 7 way but no place for the yellow wire on the 4 way flat currently in use. I see black and blue no use for elec brakes and the middle pole which has no colour indication on it. Are their diagrams for such a wire job? Thanks

asked by: Bill

Expert Reply:

There are no diagrams available for this as you would need to find the functions of the wires with a circuit tester. However, there is a much easier way to connect your trailer's 4 flat to your vehicle's 7 way with the use of a simple adapter.

So long as your connectors look like the ones in the accompanying photo you can use the Pollak 7 Pole to 4 Way Connector Adapter # PK12716, which plugs into your 7 blade and then you plug in your 4 flat. I've added a link to a video review of this adapter for you to check out.

expert reply by: Kyle S