Hello all,

I have a 2004 Expy with a factory tow hitch and 4 pin connector. I guess this means it does not have the factory heavy towing package (2wd 4.6) Anyway, I plug in my trailer and I have running light but no blinkers or brake lights on the trailer. I have checked the fuse panel on the passengers side kick panel and I filled EVERY hole with the correct fuse or relay and verified that every single fuse is good. Couldn't find any fuses located under the hood. What could be wrong here? Trailer works on other vehicles.

Also, I want to ad the 7 pin plug. Do I have any or part of the wiring under the truck? I was hoping all I need is the final few feet of the factory harness plugged in to an unused plug somewhere under my truck? Am I making any sense? I didn't see any blank plugs looking under my truck but I did notice a blue wire not used right by the 4 pin wires.

Thanks,
Chad

 

Damn, answered my own question. Since I knew the fuses were good I started tracing the wires from the rear bumper to the front of the truck. Two of the wires were cut inside the wire loom. No damage at all to the loom so I couldn't see the cuts until I actually began looking inside the loom along the frame rail. I guess someone used a floor jack or possibly a lift along that rear part of the frame right were the wires dip below the bottom of the frame a little and they got cut. Weird. It is an 04 with 16K miles. Can't imagin when it could have happened but I didn't buy it new either so who knows.

Oh well, on to my next question about adding the factory 7 pin and wires. Anyone know about doing that?

Thanks,
Chad

 

I added the 7-pin to my wife's 05 expy. It wasn't as easy as on my F150. For the expy you have to get new wiring loom from the rear bumper all the way up near the back of the engine somewhere. I remember I had to lower the fuel tank to get to a couple of the plugs. It wasn't too bad of a job, but it took some time. I never inspected the old wiring for where the differences were. If I can remember I will do that in the next week or so.

 

Cool, thanks for the heads up. Didn't realize I had to install wires that far forward on the truck. Did yours have the brake controller wires under the dash?

Chad

 

Why not use the adapter plug that Ford provides with the vehicle? It is a 4 pin to the 7 pin.