Main Relay Harness Test

Fig. 35 Main Relay Test Pins 2 And 1:

Fig. 36 Main Relay Test Pins 2 And 5:

Harness Test:

1. Keep the ignition switch in the OFF position.
2. Disconnect the main relay electrical connector.
3. Check for continuity between the BLACK wire (pin 2) in the connector and body ground.

a. If there is continuity, go on to step 4.
b. If there is no continuity, repair open in BLK wire.

4. Attach the positive probe of the voltmeter to the YELLOW/WHITE wire (pin 1) and the negative probe to the BLACK wire (pin 2).

a. Battery voltage should be available.
b. If there is no voltage, check the wiring between the battery and the main relay as well as the ECU fuse (15A) in the main fuse box.

5. Attach the positive probe of the voltmeter to the BLACK/YELLOW wire (pin 5) and the negative probe to the BLACK wire (pin 2).
6. Turn the ignition switch ON.

a. Battery voltage should be available.
b. If there is no voltage available, check #14 fuse and the wiring from the ignition switch to the fuse box, and the wiring from the fuse box to the main relay.

7. Attach the positive probe of the voltmeter to the BLUE/WHITE wire (pin 4) and the negative probe to the BLACK wire (pin 2).

Fig. 37 Main Relay Test Pins 2 And 4:

Fig. 38 Main Relay Jumper Test:

8. Turn the ignition switch to the START position.

a. Approximately 10 volts should be available.
b. If there is no voltage check the #2 (10A) fuse and the wiring between the ignition switch and the fuse box, and from the fuse box to the main relay.

9. Connect a jumper wire between the BLACK/YELLOW wire (pin 5) and the YELLOW/BLACK wire (pin 7).
10. Turn the ignition switch ON.

a. The fuel pump should work.
b. If the fuel pump does not work, check the wiring between the main relay and the fuel pump, and the wiring from the fuel pump to the ground (BLACK wire).