If fuel, temp, and oil gauges go off and on together... There is a gauge voltage limiter somwhere. If you don't find it plugged into the back of the inst' panel, it is inside a 3 post fuel gauge.
The one that plugs in can have loose connections at those strange springy female contacts in the circuit board. The center one of three contacts has additional male terminal poked in with the limiter. It comes from a noise suppression cap'. To leave it out could cause a poor connection.
The limiter inside a fuel gauge depends on a slither of metal on the back of the gauge to ground it to the inst' housing. You would need to take the panel apart and remove the fuel gauge to service this poor connection.
