My rpm gauge on my 86 brat usually doesn't work but on occation will start working. I'm assuming its a ground. I haven't tried too hard to investigate thought I'd get some ideas from you guys first.

 

 

Also anyone know if gen 1 brat canopy will fit on a gen 2?

 

I need one before next weekend for the west coast sub show and I'd like to take my pups.

The tach is run off the coil.. I do not know of any other wires for it.. Could be gauge cluster related too..

 

A gen 1 canopy will not fit a gen 2 body.

Does it play up in relation to the weather, I know mine does and I am in Sydney so it generally does not get as Cold as it can in Salem, When the car gets older the lubricant in the instruments can age and get thicker so the tach especially can become erratic and sticky and not seem to work or spin up to a certain RPM and become stuck there, Just a thought I have a mate who is a Scientiffic Instrument maker and he clued me up on this one it may well not be electrical on older vehicles.

It just seems stuck.

Ill have to continue investigating