How To Connect Boat Trailer With 5-way Connector To 2014 Ford Expedition With 4-way Connector

Question:

am about to rewire my boat trailer. currently 4 wires go all the way back on the trailer, 1 grey, 2 grey and yellow, 3 yellow and grey, 4 aqua and grey. also 1 white wire grounds to the trailer. 6th wire is royal blue and is disconnected around the surge brake module behind the hitch. On the 5 pole connector, white is connected to pole 1, both greys to pole 2, yellow and grey to pole 3, aqua and grey to pole 4. Unhooked royal blue goes to pole 5. When i currently plug 5 pole trailer to 4 pole 2014 ford expedition, i just leave pole 5 the royal blue hanging off the end. I was going to replace the 4 wires that route to the back of the trailer w new 16/4 yellow/white/green/brown. should I replace my 5 pole w a 4 pole? if i want to use the 5 pole and hook up the royal blue wire to the surge brakes, how do i connect the royal blue wire to my expedtion, which only has a 4 pole and 7 pole socket, but no 5 pole socket?

asked by: Jamie S

Expert Reply:

You are correct that the 5th wire of the 5 pole connector you have on your boat trailer is for connecting to an electric lockout solenoid on a surge brake actuator.

If you go ahead and connect the wire to your surge brake actuator on your trailer, you will need to add the Curt Trailer Connector Adapter - 4-Way Flat to 5-Way Flat - Vehicle End # C57187 to the 4-way connector on your 2014 Ford Expedition. The blue wire on the adapter will need to be connected to the reverse light circuit of your Expedition with the included quick splice.

To find the correct wiring you will need to use a circuit tester like the # PTW2993 and have a buddy put the vehicle in reverse, but keep their foot on the brakes, while you find the correct reverse wire.

I included a video of the # C57187 for you to take a look at.

expert reply by: Samuel C