Replacing 4-pin Plug with a 5-Way Plug So I Can Back My Trailer
Updated 08/03/2009 | Published 07/30/2009 >
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Question:
Will this kit replace my standard 4-pin wiring harness to allow me to use the 5-pin on my trailer and allow me to use my trailer in reverse? If so, how is it wired to the truck without splicing?
asked by: John F
Expert Reply:
If you have a working 4 pin trailer connector and a boat trailer with surge brakes, then you will not need a 4-pin wiring harness. If your trailers 5-pin connector is the flat style you can use the 4 Pole to 5 Pole Trailer Wiring Adapter, part # 47515, and splice it into the reverse light circuit behind one of the taillights with the quick splice that is included with the adapter. If you need an extension for your trailer connection to mount the five-pole connector to a bracket, part # tr20046, you can use part # 20036. You can remove these adapters from your 4-way flat connector by unplugging the adapter and the blue backup wire from its connector that is provided.
If you have a 5-way round connector on your trailer you will need to splice into the 4-way connector on your vehicle. If you want to retain the 4-way or replace the 4-way connector with a 5-Pole Round Pin Trailer Wiring Socket, part # PK11502, you will need a circuit tester, part # PTW2993, to find the backup light circuit behind one of the taillights.
You will use the four wires from your 4 pole and splice a blue wire to the vehicle backup light circuit.

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