My pressure gauge is not reading right!
Ensure you are using our sensor, most other sensors will not work with our gauges.
With the harness disconnected from the sensor and the gauge powered on, measure the voltage across the red and black wires in the harness at the sensor end. Here you should see 4.9-5 volts.
Once you have confirmed the voltage, short the red wire to the white wire, this should make the gauge sweep full scale.
With the harness still disconnected from the sensor, go to key-on or start the car. With the sensor disconnected the gauge should stay at 0 or the bottom of the scale.
If all those turn out normally, next we'll test the sensor. Disconnect the harness from the gauge, and reconnect it to the sensor. Measure voltage between the white wire (signal from sensor) and black wire (ground) and you should see a range between 0.5 to 4.5 volts. You will need to supply power and ground to the sensor while it's disconnected from the gauge. You can use short paperclip pieces if needed.