The same thing happened on my 89 100, only the idiot light stayed on all the time. With the oil pressure gauge there to tell me all was OK I determined the sensor was bad and disconnected it. I would rather have it working but not enough to spend the $. bye, David Conner conner@cfm.ohio-state.edu 614-292-1619 (voice) 614-292-8062 (FAX)