Operation CHARM: Car repair manuals for everyone.

Main Relay (Computer/Fuel System): Testing and Inspection


Main Relay Location:





1. Check that a "clicking" sound is heard at the main relay when turning the ignition switch OFF and ON.

Testing Main Relay:





2. Apply 12 volts and a ground to terminals "5" and "6" of the main relay as shown in the diagram.
3. Check for continuity at the terminals with an ohmmeter. With 12 volts applied to the terminals, there should be continuity between terminals "1" and "2" of the main relay. There should also be continuity between terminals "3" and "4". With the voltage removed, there should be no continuity between terminals "1" and "2" or between terminals "3" and "4" of the main relay.
4. If not correct, replace the main relay.