Installing a 5-Way Flat Trailer Connector on 2005 Ford Explorer for Boat Trailer with Surge Coupler

Question:

I have an 2005 Ford Explorer and I need a boat trailer hookup for a 5 flat plug. What do I have to do to hook this trailer up with the surge brakes.

asked by: Marshall G

Expert Reply:

If your Explorer already has a 4 pole trailer connector on it, you can install a 5-pole connector. Use a 5-pole vehicle side trailer connector part # HM37908, and after cutting off your existing 4-pole, wire the green, yellow, brown and white wires of the 5-pole into the wiring harness on the vehicle. The remaining blue wire on the 5-pole would tap into the reverse lamp circuit on your Explorer. Once the transmission is placed in reverse, the reverse lamp is lit, sending a signal to lock out the surge brake coupler allowing you to back the trailer without the brakes locking up.

If you would rather use an adapter, you can use part # 20036. Like I outlined above, the blue wire would tap into the reverse lamp circuit.

If you do not have a trailer connector, the # HM37908 would tap directly into the lighting circuits that feed your taillight assemblies. I will link you to a video showing how to use a circuit tester like part # PTW2993 to locate which circuit serves which tail light function.