car gets warm or sits in the sun and then the speedo and tachometer and odometer dont work? probably a bad connection or broken wire in the circuitboard of the gauge cluster.





IGN + wire powers the lights and the tach and speedo all in a parallel circuit. an open connection appears when the car sits in the sun or the cabin heats up, check it with a multimeter.
the open circuit will probably be where the circuit bends over the edge




use conductive silver epoxy or solder to jump a wire from one of the unused bulbs to the speedo + screw.

that's how i fixed the issue, works just like new now. I soldered the circuit but the heat from the iron peeled back the copper connection, so conductive epoxy is probably a better option. to find the open circuit with a multimeter you may need to replicate the conditions (the heat of the car) so hold the cluster over a stove element until its "car in sun windows up" hot.