Adapting 4-Pole on 2005 Ford Explorer to a 7-Way for Towing a Boat

Question:

I have a 2005 Ford Explorer XLT 4x4. It came with class III hitch and also factory 4 way flat. I am needing to change that to 7 way for a boat. What would I need? Do you have a T adapter then the 7 way and still be able to keep the 4 way? Please advise.

asked by: Scott E

Expert Reply:

Since boat trailers don't typically have electric brakes, I'm assuming you mainly need the 7-way for the lighting circuits and perhaps for an electric reverse lock-out solenoid on a hydraulic brake actuating trailer coupler.

The Hopkins # 37185 adapter will plug directly into the4-pole that's already installed on your Explorer and provide a functioning 7-way, as well as retaining an operational 4-pole. The adapter will have four remaining wires. The blue wire would usually be used to carry the brake controller output voltage to the trailer brakes. Since your boat almost certainly doesn't have electric brakes, you can simply coil the wire up out of the way in case it's needed later. The white wire is grounded to the vehicle frame, and the black wire which usually carries the 12-volt accessory circuit from the vehicle battery for any trailer mounted accessories that might need it can also be bundled up and tucked away for future usage. If your boat trailer has a surge (hydraulic) coupler that has an electric lock out that keeps the brakes from functioning when you reverse up a hill, you'll need to tap the purple wire into the reverse lamp circuit of your Explorer. Otherwise, bundle up the wire and tuck it away with the rest of the unused wires.

expert reply by: Mike L