Jumpy Noisy Tach

[longbedder]

Vehicle = 1994 Burb with factory tach.

The tach drive motor is noisy as hell, and recently the needle has started jumping +/- about 200 RPM (actual engine speed constant). Anybody have any similar experience?

Were you able to either fix it or replace only the tach without replacing the whole cluster?

 

[noJeepshere]

dirty wires or a bad ground, my guess. our school busses do this and the mechanic has it done in 10 mins. ill ask what they do tomorrow.