I have a 1968 4 door Lincoln Continental with the 462 engine. When I turn the key off the engine will not shut off, unless I turn the radio on?? I have replaced the Alternator and Voltage Regulator, but the problem has not gone away. It is like the coil is getting a back feed through the circuit somewhere. Any help you can give would be appreciated.
Thank you, Regards,
Greetings Aaron –
Some of these types of issues can be time consuming to diagnose but accurate diagnosis is very important. You need to know a few things about your car before trying to uncover the actual problem.
Did the problem begin after some” recent” repair or addition to the vehicle?
Do you have a non factory ignition system (Petronix etc)?
You could start testing at the ignition coil with the key in the off position and with the engine off. If you have power at the coil in this position you would need to test why power is available there in this off position. A proper wiring diagram and 12v test light is a must for the testing. The power path will lead from the coil to the ignition switch and also to the starter solenoid. A short inside the starter solenoid could cause the coil to be powered up with the key off. Unplugging that wire at the starter solenoid will remove the power to the coil if the solenoid is faulty. The other possibility is that the ignition switch or its electrical connection is shorted. Unplugging the ignition switch and carefully inspecting the plug will remove power to the coil if there is a problem in that area. You can observe the power at the ignition coil with every disconnect that you do to find out if that component is shorted etc.
I have no idea what the radio could have to do with your problem unless some unknown wiring deviation was added to your Lincoln. Do you know if any non factory wiring was ever added to your vehicle?