My tow rig, a 97 3500 Cummins, has developed a strange problem. The Tachometer is jumping all over the place. It does not read accuratly. It jumps to 5000 then back down to 100, boucning all over the place. This triggered the check engine light to come on and then my cruise control stoped working. It happened so suddenly.
I took it to my buddy at the dealer and he hooked it up to the diagnostics and said that everything checked out. He thought that maybe it is the crank sensor. I really don't want to start replacing Misc. parts in hopes that that is the problem.

Has any one had a similar problem? Got any advice?

What codes came up with the MIL (check engine light)? They should have pointed your buddy in some kind of direction.

What codes came up with the MIL (check engine light)? They should have pointed your buddy in some kind of direction.


While at the dealer no error codes came up. So I am really stumped. :confused: