1978 F-150 odd starter issue
I am rehabilitating a 1978 F-150 (300ci straight 6, 4WD) and I am having the oddest starting problem. The engine will start and run only as long as it is being cranked. When the key goes back to the run position, no ignition and engine shuts down.
Things I have done:
1) Replaced starter (it was seized up)
2) Replaced solenoid (just because)
3) Replaced the big fuse that is screwed to the body next to the solenoid
4) Yanked out the ignition switch and checked its function
5) Traced wiring continuity to and from the starter switch
I'm sure that the problem has a simple solution, but I am at wits end trying to figure out what is going on. It seems like there is no juice coming out of the "I" terminal on the solenoid. If I short the S and I terminals when someone is cranking it, it starts up and stays running, but the starter keeps going so I obviously can't leave it like that except for test purposes.