Control Relay (Fuel Pump Control) Test

Control Relay Location:

CAUTION: When applying battery voltage to the Control Relay, verify that the power source connections are to the correct terminals. Incorrect connections may damage the relay. Perform the following test procedures in the order instructed, to prevent inaccurate results, and possible relay damage.

Control Relay And Connector:

1. Disconnect the control relay electrical connector, and remove the relay.

MPI Control Relay Circuitry:

2. Connect a lead wire with alligator clips from the positive terminal of the battery to terminal 10 of the relay, and connect another lead wire from terminal 8 of the relay to the battery ground.

Checking The Control Relay:

3. Measure across terminals 4 and 5 of the relay with battery voltage connected. The reading should be 11-13V at both terminals.
4. Disconnect the negative lead wire from terminal 8 of the relay to battery ground, and recheck for voltage at terminals 4 and 5 of the relay. There should be no voltage present.

Checking The Control Relay:

5. Connect the positive lead wire from the positive battery terminal to terminal 9 of the control relay. Connect the negative battery lead to terminal 6 of the relay.
6. Measure across terminals 2 and 3 of the control relay with battery voltage applied using a continuity tester. There should be continuity between the terminals. Remove the negative battery lead from terminal 6 of the control relay, and recheck for continuity. There should be no continuity with battery power removed.

Checking The Control Relay:

Connect the positive battery lead to terminal 3 of the control relay. Connect the negative battery lead to terminal 7 of the relay. Check for voltage at terminal 2 of the control relay. The reading should be 11-13V with battery power connected. Remove the ground lead and recheck for voltage. The reading should drop to 0 Volts.

Replace the control relay if the results of any of the tests are unsatisfactory.