1992 GMC Sierra not shutting down
I have a 92 GMC 4 x 4. When I shut the
ignition switch off the truck stays running. It
is not dieseling. In order to shut the truck off I
have to pull the ECM fuse. We have replaced
the ECM and this didn not fix it. The key
switch is in the off position and still running.
Disconnected the alternator and still runs. I
feel that it’s feeding voltage back in to the
ECM we cannot find out what would be
doing it.