Just recently picked up a 2004 Chevy Silverado 4x4 5.3 L with 233K for only $1,800. When I bought the truck, the seller told me it was stuck in 4Low and the starter engages when the key is turned to the run position. After looking into the fuse box, I noticed a wire was chewed through and after I fixed the wire, the 4x4 works perfect. The truck will still start, the starter just engages early and will keep cranking if left in the run position. I have checked multiple grounds and wires, and just tonight I replaced the ignition switch. None of these have worked so far and if anyone has some advice that would be great. From my knowledge, the starter is getting voltage in the run position, when it shouldn't. I just don't know why or where to look.

Side note: Before replacing the ignition switch, I pulled the old one out and inspected it, and then put it back together. After, the starter would act normal and would NOT engage in run. The next day, it went back to cranking in run.

My buddy and I took the truck for a drive and everything was going pretty smooth. The transmission seemed hesitant to shift in 3rd but I believe it was just low on fluid. While driving, the truck would have that "fall on its face feeling" and then lose power and shut off. Although the dash lights and everything else would stay on. Any advice would be appreciated.

Another side note: When scanning the truck while its running, the TPS says its at 17.6 WITHOUT my foot on the pedal. When you press the pedal, it does go up but doesn't seem to be accurate.

 

My customer had same issue with starter engaging in the run position even after new starter was installed and Ignition switch was replaced. Turn out to be a problem with the transmission PNP switch. Water has gotten into the switch causing this issue.

 

Have you checked the starter relay?

 

@chem_man the question was asked over 3 years ago