I agree I would definetly want to scan it. I remember on cars that I actually had bad clocksprings cause TPS problems which could cause the problems you have. Not sure how it will effect your truck without looking at the wire diagrahm. On some the 5 volt reference feed to the clockspring for the cruise switches also fed the TPS 5 volt feed and I had seen the clockspring under the steering wheel short voltage from the horn circuit to the 5 volt feed. I remember well because the TPS voltage reading on the scan tool was not steady and jumped around and read different then what I read on the 5 volt circuit with my Fluke Meter when I back probed the circuit. When I unhooked the clockspring the TPS read normal and everything worked fine other then the cruise and horn of course since I had the clockspring unhooked. Dont know if that could be your problem but a quick scan with the scan tool will tell you a ton about the circuits. I remember it well because the vehicle was sent to our dealer from a service station and the tech from the service station called me to ask me how the closkspring could fix the problem it had. He was a good tech as I knew it once he talked to me and he wanted to know why that fixed it ? Being I worked at the Dodge dealer I had more info for me to use then he did but a good tech always wants to know just how the part they put on fixed it and he went out of his way to talk to me and find out just what fixed it. Ron