The selenoid inside is stuck, get a new one, they aren't too expensive.
The starter solenoid is not disengaging once engine is started. Rebuild starter or replace with a new starter.
Your starter solenoid is sticking. Replace the starter solenoid and you should be good to go.
The signal for the starter originates from the key switch, I would start there.
The starter solenoid is sticking or stuck.
Sounds like starter drive is not releasing--perhaps a bad starter solenoid
Mainly it is for the starter motor. Once it's running, it's quite common that a car will keep running from the alternator even if the battery is dead. But without being able to use the starter motor, getting it going is quite tricky.
Certainly. Once the engine is running the starter is not needed.
No, I would seek another answer to the problem. If the starter starts while the car is running, it may grind the bendix or the starter into a toothless nub and the starter will quit functioning alltogether.
Yes. The alternator is used to keep the battery charged, while using the headlights, radio, a/c, etc. The starter to me is misstated because it actually cranks the engine. The ignition system starts it, and keeps it running.
The starter needs power to crank the engine to get it running. Once the engine is running however, the alternator generates enough power to keep it running. But with no reserved power (a battery) the car cannot turn over.
I would suspect a defective ignition switch. I would be more inclined to believe it was the starter relay/solenoid thingy i used to have an old amc eagle. and it did same thing starter wouldn't disengage. I replaced the solenoid/starter relay and it worked fine after that.
If the starter is whining while the engine is running at an idle you have a problem with the ignition switch or the starter solenoid is stuck. The starter should not be engaged while the engine is running unless you are holding the key over on the start position.