I have a 2003 F150 with the 2v 5.4l 4 wheel drive. It has come to me that they have the common issue of having a wiring harness that runs down the passenger side to the transmission and catches contact with the passenger side manifold. I have re wrapped it several times because every time the coating melts and exposes the bare wires, it cause all transmission solenoid to short and i think it has cause my o2 sensor to go out. I want to replace that wiring harness but in doing so I need to know what I'm searching. I have looked everywhere and have tried search for "transmission wiring harness" or "harness that connects to the o2 sensors" and nothing that I'm looking for will come up. Not even searching for what the harness is called is helping. I've tried looking at diagrams to see if I can't trace it to find what its called or the part number but absolutely shows up. If someone could help me out by giving me the proper name for it or the part number that would be great. The harness lays on top of the transmission and connects to all sensors near the transmission. Please help I don't want to keep patching this. if i could get a fresh new harness for it then rout it away from the manifold it would make owning this truck a lot easier.

 

@Aspen0524 What model transmission do you have? 4R100 or 4R70W.

@brianmagoon any chance you kept the wiring harness from the 2003 F150 transmission?

If he doesnt have the harness your cheapest bet would probably be to go to pull a part and find a F150 with the same transmission and take the harness off it.