Inherited a '00 trailblazer that did not run. Key switch had been messed with but seems to funtion. Handle bars had been bent back (wrecked?) with loose switch connections.
Turned over fine but not spark (new plug). Then unpluged black wire (kill system) and had spark and ran but could not shut off. Trying to figure out what to check next. I assume since in ran that CDI box is ok and secondary coil ok. Now thinking maybe reverse limit or rectifier may be bad but don't know how to check. Could it be a grouding issue? I don't want to start replacing big $ items trying to find the problem if it can be something simple. Don't know were to go next.
Thanks

 

sounds like just the kill switch is grounded out to me - have you traced it back? You said it has loose connections