Occasionally, my starter will not disengage when I release the ignition key, and I have to turn the car off, and the starter keeps cranking, so I have to get out and pull the battery cable off. I already replaced the solenoid once. What gives? Crappy parts from NAPA? Or am I burning them up with too much voltage? Need a new regulator? New alternator?
Sounds like a defective solenoid. Next time, just before you pull the battery cable, first pull off the small wire next to the battery cable. Just make sure your not getting a stray voltage to the start terminal. If it still continues to crank, I'd try another solenoid.
Nothing wrong other than your battery is too weak to crank it. You need a fully (or close to it) charged battery to keep the solenoid from doing this. Once you reconnect a freshly charged battery and it's still stuck, tap on the solenoid to unstick it.
It's still possible you have a bad solenoid if your battery does have a good charge. Like stated, check your battery first. If you have to replace the solenoid again, be sure that when you tighten the nuts holding your cables on that you don't overtighten and make the entire terminal twist inside the solenoid. If you happen to make the contacts twist you can wind up with this same problem.
I would check the battey and do as stated above. Also have your recently switched from points to electronic ignition? if you have i think you only use one of the small wires at the soleniod instead of both. I went thru 2 GP sorensons that did the same thing straight out of the box before i used an old one off of a junk car that works perfect. If you have to replace it again i would suggest an oem part for this.
