The problem: When key turns to start starter engages but when I turn key from start back to run starter still is engaged even though engine is already running and the only way to disengage the starter is to disconnect the battery or SOMETIMES turn the key back and forth until the entire system is successfully turned off. I have already replaced the starter, starter solenoid, and ignition switch (key module). So I don't know what the problem is. I think I just toasted my starter now too. Any thoughts? Does anyone have a simplified wiring diagram showing just the ignition related wiring?

 

Internal steering column actuator for the ignition switch can get gummed up/sticky keeping the actuator from releasing the ignition switch. Not likely to be a fun easy project. However, given that you have replaced all of the electrical components involved, its the most likely culprit I can think of.

 

Im not sure if I understand, The Ignition switch on the 79 is on the dash not the steering column.