Installing an Electric Trailer Brake Controller on a 2006 Ford Expedition with Factory 4-Way

Question:

Looking at my existing 2006 Ford Expeditioin, Eddie Bauer, in preparation to install a 7 pin adapter and brake controler, I find a dark blue wire in a factory sheath coming out of the larger sheath that houses the wires to the existing 4 pin plug. This dark blue wire in its sheath comes out of the existing larger sheath about 3 from the end of the 4 pin and is fastened to the larger sheath running on to the the 4 pin. My question: Would the blue wire be used in the 4 pin to 7 pin conversion? Do I still need the the ETBC7 conversion kit for my 2006 Ford Expedition, Eddie Bauer, factory standard hitch configeration? Thanks for all your help.

asked by: Alex H

Expert Reply:

The blue wire that you have mentioned could be functional, but you will need to test it. You can test it 1 of 2 ways. First, you can install a brake controller using the vehicle specific harness for your 2006 Ford Expedition. I recommend the Tekonsha P2, # 90885 and the Ford wiring harness # 3035-P. You will plug the wiring harness into the port located under the dash, to the right of the steering wheel, then connect the other end to the back of the P2.

With the brake controller plugged in, have someone apply the manual override lever and hold it while you test the blue wire at the back with a circuit tester like # PTW2993. If the test lamp lights up with the lever engaged or brake pedal pressed and shuts off with the lever or brake pedal off, then this wire is the brake output wire and it can be used when installing the required 7-Way wiring harness, # 37185.

Another way to test the wire is to use a separate power source, like a 12-volt battery, and run power from the positive terminal along the pin on the port under the dash that is for brake output and test the wire at the back like explained above.

If you find that the wire does not contain the brake signal, then you will need several components of the # ETBC7 but not the entire kit. To begin you will need to route a length of # 10-2-1 wire. This is a duplex cable sold in 1 foot increments. Since the Expedition is a longer vehicle, I recommend at least 25 feet. Use the white wire for the # 37185 blue wire and the black wire for the black wire on the harness. After making the connections, route the wire under the vehicle, avoiding areas that may pinch or burn the wire. The white wire will need to be routed to the brake controller. You will need to sever the blue wire on the # 3035-P harness behind the end that plugs into the vehicle. Attach the wire you ran from the back to this wire.

The other wire will need to go in the engine compartment near the battery. Mount a 40-amp circuit breaker, # PK54540, near the battery. Run the wire to the circuit breaker with enough slack to reach the AUX post. Clip off any excess wire and make the connection to the AUX post. Then, connect an end of the wire you clipped off and attach it to the BAT post. Then route the other end and attach to the positive battery terminal.

The remaining wires on the # 37185 will need to be hardwired. White will ground to the vehicle frame and the purple wire can be attached to a reverse light wire behind one of the taillights. If it is not needed, it can be taped up and stowed out of the way.