Hello, I have a 98 Monaco Signature with a 500 Cummins N-14 Celect +. The tachometer after a few minutes gets to bouncing and goes all over the place. If anyone knows Cummins, does the tach signal come from the alternator, or does it come from the EEC? The N-14 was the first Electronic Engine Computer model, and has a history of computer problems.
Thanks for any help!