94 Camry, tach and odomoter work but speedometer stays at zero. Car is new to me so don't know how long it has not worked. Looking for suggestions as to where to start my troubleshooting.

 

Speedo is electric and uses a speed sensor mounted on the trans (has 3 wires). Find sensor and check plug connection and wiring. Sensor could be bad but rare.

 

Thanks. So you're saying to use my tester to check voltage at the sensor plug, because lack of power to the sensor is a more likely problem than the sensor itself being bad? I did not even think of checking a fuse or relay because I presumed the tach would be running off the same circuit. Is this the case? If not then obviously I need to check fuse before even bothering with checking sensor plug.

 

The system uses the Gauge fuse. This fuse also powers the gauges and many dash indicator lights thus if blown they would not work. However the sensor receives power from the fuse via the red/blue wire. Check for +12V at this wire on plug.

The sensor generates pulses (digital), not voltage (analog). The pulses are counted by a circuit inside the dash console and converted to a voltage to move the speedometer arm.

There are no relays in the circuit.

The speedo system connects to the cruise control system. Might determine if the cruise system works and if so then could only be problem with the speedometer itself.