Ensure that the issue is with the speedometer: Turn the ignition key to the "On" position without starting the engine. If the speedometer needle doesn't move or doesn't indicate the correct speed, there's an issue.
Check the fuses: The speedometer fuse may be blown, so inspect the fuse box located in the driver's footwell or engine bay. If the speedometer fuse is blown, replace it with a fuse of the same amperage.
Inspect the speedometer cable (if applicable): Older vehicles like your 1993 Camry may use a mechanical speedometer cable that connects the transmission to the speedometer. If your vehicle has this cable, check for damage or disconnection.
Test the speed sensor: The speed sensor is responsible for sending speed signals from the transmission to the speedometer. Locate the speed sensor (usually near the transmission or the rear differential) and check its connection. Clean any debris or corrosion around the sensor and ensure it is properly connected.
Verify the instrument cluster: If the speed sensor and cable are working correctly, the problem may lie within the instrument cluster itself. There could be a faulty connection or a problem with the speedometer mechanism. To check this, you'll need to remove the instrument cluster and inspect it. It's recommended to consult a qualified mechanic or auto electrician if you're not comfortable doing this yourself.
Note: If you suspect that the issue may be electrical or requires specialized repairs, it's advisable to take your vehicle to a qualified mechanic for accurate diagnosis and repair.
