Help!! My tachometer on my 97 3500 has been erratic for the past couple of months. Yesterday it quit working altogether and stays at 0. I have no higher gears in the automatic tranny and altimeter shows it is not charging. Any help would be most appreciated.

 

First thing, next to the oil fill tube will be the connector for the engine speed sensor, check it for corrosion and clean it good. Oftentimes it gets gunked up and it loses the signal. Use either contact cleaner or brake cleaner, dry it well and put it back together.

If that doesn't do it, then it may be time for an ESS, or find the break in the wire.

 

Thanks. Tried cleaning the old one to no avail. Put the new one on today and it works great.