I used to have a 1993 Ford Crown Vic PI and my speedometer didn't work either. My mechanic said its connected to the transmission; the wirng must be either broken or not connected. Ask a mechanic if this is the problem.
If a 1992 Honda Civic's speedometer is erratic, the problem could be the speedometer cable. It could also be the speedometer sensor malfunctioning. Check both components carefully.
You have a bad Vss Sensor.............. The vehicle speed sensor.
check fuses
It died of Chevy Envy
Could be a loose ground wire
Either a problem in the circuit or a faulty vehicle speed sensor.
The speedometer and odometer may stop working in a Nissan Pathfinder due to an electrical short. It may also need a new spark plug.
check the fuses. Same thing with my 96 corsica, along with a few other instruments.
They both work off of the same signal. If the speedometer works but the odometer doesn't, the odometer has failed.
a 1992 Volvo 940 doesn't have a speedometer cable. the speedometer is controlled electronically.
Sometimes switches wear out, which could be the reason the switch in your 1992 Chevy truck is not working. There could also be a problem with the wiring. You may also want to check the fuse for the blower to see if it's bad.
Vehicle Speed Sensor