Ok new here. I have been scratching my head for weeks now. I’m decent at working on my vehicles. Especially my 1988 F250 7.3 IDI 5spd. So I was headed to work one morning, my radio shut off and back on a couple of times, then started hearing squealing out of the truck. Volts were low, figured the rebuilt alternator was giving up. So rushed to work and shut it down. When I went to restart it nothing. What I was really hearing was the starter engaging while heading down the road. Got new starter on but it now try’s to crank in the run position not the start position. Thinking it was the starter switch I replaced it still did it, tried a new solenoid still doing it. The signal wire to the solenoid only gets fire in run position and test light barely lights in start. And it does it no matter position of the clutch and have even pulled the plug off the clutch position switch and it will still do it. For some reason that morning it was try to crank because it got power to the solenoid while I was headed down the road. Anybody have any ideas on what to try now.