engine won't shut off until low idel. it appears when alt charging there is feed to ign. stumped,any ideas would be appreciated

I have a one wire alternator and have not experienced this. How do you have it wired up?

Durham Missouri

replaced the solenoid(made in tywan) appears to have corrected issue. as i had terms 2 (small 2) hooked up to give coil full voltage i think that terminal had a minute leak giving the dura spark enough to keep engine running when it slowed enough that alt. was no longer charging i could kill engine at idea.??