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

Fig. 16 Checking main relay voltage:

Fig. 17 Checking main relay resistance:

1. Check main rely for sound of operation when ignition switch is turned ``On.'' If no sound is heard, proceed to step 2.
2. With ignition switch ``On,'' check voltage between terminals as indicated, Fig. 16. The same component is used for main and fuel pump relay. To identify main relay, check lead wire for black, black/white, white/blue, and white/green wire.
3. With ignition switch ``Off,'' remove main relay and disconnect electrical connector. Check resistance between each terminal as shown, Fig. 17.
4. Check for continuity between terminals 3 and 4 when battery voltage is applied to terminals 1 and 2.