Kingston key off but engine sill idling

[sagaboy]

When I turned off the ignition key, the engine continues to idle, with the key still in the off position the charging light comes on but idling continues.
A) I have removed the ignition key switch and tested it, it is in good working condition... That is in the key off position the battery contact to the other contact are turned off.
B) I have checked the fuel cut off solenoid, found it faulty totally not working when connecting to 12v supply and have replaced with a new tested and working fuel cut off solenoid BUT with key in off position engine idling still continues to run.

C) with solenoid in position at the carburetor, I tested 12v supply with key off and on... OK power goes off n on at solenoid.

What else do I need to check?

Appreciated any suggestions, thank you.

[SCOTTRODS]

Any aftermarket audio stuff? any aftermarket anything? Year and model of original wiring harness? More info needed for even the best "online troubleshooters".

[Marc]

When I turned off the ignition key, the engine continues to idle...with solenoid in position at the carburetor, I tested 12v supply with key off and on... OK power goes off n on at solenoid...

The idle cut-off solenoid should be receiving power from the same place that the coil does (the C/O jet and choke are normally wired directly to Term 15 of the coil). A static test of power to the C/O jet doesn't address the issue you describe, which occurs with a running engine.

Some aftermarket ignitions will receive enough power from the alternator to keep the coil energized (power backfeeds up the warning-lamp wire).
The warning light isn't polarity-sensitive, it has no brains and will light if there's sufficient voltage differential in either direction. Turning off the key interrupts power to one side of the lamp; if it's lit there must be power to the other side.

So-o-o-o, at this distance, my first suspicion is that you need to add an isolation diode to the charging system warning lamp wire.

http://www.msdignition.com/page.aspx?id=3296

If you have a generator, with external regulator, the culprit would be sticking cut-in contacts in the regulator....that'll also keep battery power applied to the generator windings with the engine off; since the generator can't develop enough torque to turn the engine over, it'll just sit there heating up and draining the battery.

[FJCamper]

Hi Sagaboy,

If you are Catholic, get a priest for an exorcism.

If not, listen to Marc.

FJC

[sagaboy]

Marc, TQ.
Let me wire/solder a diode to one side of the alternator warning lamp and hopefully solve the problem.

[sagaboy]

It worked. The engine stop running after cutting the wire to the charge lamp indicator just outside the speedo meter and sloder a 1n2002 diode between the spliced wire.