I could use some advise. My wife has a 1965 Mustang and the starter is "sticking" and continues to crank over even after the engine has started and is running. Can't switch it off by the ignition. I have to pull the "hot" terminal off the battery. We replaced the solenoid (four pole) which is mounted on the passenger side fender well about four months ago because the engine would only start sporadically. (The car might turn over and start ten times and then leave you stranded at the parts store.) In fact I have replaced the solenoid three times. I have checked and cleaned every wire connection under the hood multiple times. Thank God I have a '73 F100 and am not having any problems. Gotta love a truck!

 

Assuming the solenoid is not "sticking", which seems likely since you replaced it, you need to be aware that there is also a solenoid on top of the starter motor. It's duty is to quickly push the starter drive, which is a one-way clutch driving a small pinion gear, in to mesh with the flywheel ring gear. There is a large set of contacts within this solenoid which actually turn the starter ON. They can become welded together, causing the starter motor to not shut off. I would almost bet on that being your problem. Repairable, probably, but easiest fix is a new starter.

BTW, your F-100 uses the same starter and is prone to exactly the same kind of malfunction.

 

thanks for your feedback, gonna go ahead and look at getting that starter replaced and pick up a new solenoid too. Heard a heavy duty was the way to go.