jumping oil pressure guage

Looked over the forums and TMs but could not find anything that matched...

During the recovery inspection the guage worked good. After getting on the freeway I noticed the guage continually jumping from 0 to max. When we pulled over to check things out, the guage was again reading properly. Did this the whole way home, 350 miles. Seems to only happen when on the road, 40+. Any ideas? Ground?

All of the other guages seem to be working ok, at idle or at speed.

Check your battery connections.

The only ground on the gauge is its mount. I had to shim mine to get it to work.

Thanks for that tidbit - mine does something similar. Every time you tap the glass on it, you get a slightly different reading =|

I'll remount it this afternoon to hopefully redo the ground