Testing Fuel and Temperature Gauges

TECH TIPS

TESTING FUEL & TEMP GAUGES

To test your temperature or fuel gauges to determine if the gauge needs to be replaced or calibrated, the following techniques will help.

6 volt applications: If you pass a 1.5 volt charge across the fuel gauge posts and the gauge reads 1/2 scale, then the gauge is okay.
If you ground the temperature gauge when the car is cold, it should go all the way to the HOT side of the gauge.

12 volt applications: For the fuel gauge, when passing a 3 volt charge across the posts, it should read 1/2 scale, or 4 volts should read 3/4 scale.
For the temperature gauge, 3 volts should read 1/2 scale, and 4 volts should read 1/4 scale.

From ThunderEnlightening, Casco, November 2008