Although it hasn't done this in many years, the gauges in my 1985 used to go haywire
and scare me to death
about twice a year.
The first thing I would notice was the temperature gauge all the way past
HOT.
After the initial heart failure, I would then see that all the gauges had went all the way to the right.
Quite by accident, I found that a few light taps on the plastic window just in front of the speedometer would bring things back to normal.
I never did actually find why this would happen.
Whatever, it must have went into remission, as it hasn't done it in a long time.