Converting a 4 Way Connector to a 7 Way Connector on a 2006 Ford E-250

Expert Reply:

The wires for the trailer brake output and 12 volt power are not located at the rear of the van on the 2006 Ford E series. If you are towing a trailer with electric brakes, then you will need to install a 7 way adapter, part # 37185, to properly connect your trailer to your vehicle.

The trailer brake and 12 volt power wires will need to be ran from the 7 way adapter to the front of the vehicle. You will need to get the appropriate length of duplex cable like part # 10-2-1, probably around 25 ft, and the white wire will connect to the blue wire on the 7 way adapter and the black wire from the duplex cable will connect to the black wire from the 7 way adapter. There is a connection point on the adapter for your existing 4 way connector and then you can ground the white wire from the adapter to the vehicle frame and tie off the purple auxiliary wire if the reverse light circuit is not needed.

The white wire connected to the blue brake wire on the 7 way adapter can be ran into the cab through any available slot in the firewall and there are two options for connecting it to the brake controller. You can cut the brake output wire that is going to the brake controller port on the vehicle and use a butt connector like part # 05732-2 or you can cut the blue wire coming from the brake controller wires and connect that blue wire with the white wire from the duplex cable. The first option will allow you to remove your brake controller easily at a later point and the second option would be a more permanent solution.

You will need a 40 amp circuit breaker like part # PK54540 to run the black 12 volt power wire to under the hood. The black wire from the duplex cable will be ran to the silver side of the circuit breaker using a ring terminal like part # DW05705-1 and you should have enough left over cable to run a wire from the copper side of the circuit breaker to the positive terminal on the battery. This will give you power to your 7 way adapter. I have included a video of the installation of these wires on a 1996 Ford Explorer. The vehicle is different from your 2006 Ford E-250, but the wiring process under the hood will be the same. You can disregard using the second circuit breaker for the brake wire because you already have a brake controller port available under your dash.

If you did not want to buy all of the parts separately then I would recommend the Brake Controller 7 and 4 Way Installation Kit, part # ETBC7. This will provide you with the 7 way adapter as well as the additional wires for brakes, power and auxiliary wires needed to use the electric brakes on the trailer. I have included a demonstration video for the 7 and 4 way installation kit as well as an article for wiring the installation kit.

expert reply by: John H