Fuel Pump Control Unit: Testing and Inspection

1. Disconnect control unit from harness connector.

2. Check continuity to ground at the terminal with the black wire.

^ should have good continuity to ground.

If not, repair wiring.


3. Turn ignition "ON" and check voltage at terminal with B/W wire.

^ should have battery voltage.

If not, repair wiring between control unit and ignition switch.

4. Reconnect control unit harness connector and disconnect fuel transfer pump electrical connector at the fuel tank.

5. Turn ignition "ON".

6. Check for voltage with the ignition "ON", at fuel transfer pump harness connector terminals as listed below.

Transfer Pump Connector:

WIRE COLOR CODE - VOLTAGE

White/Green (both) - 12 volts (power to transfer pump)
White/Black - Greater than 1.5 volts (float switch)

If voltages are OK, control unit is OK.

If voltages are not correct, check wiring for open or short to ground.

If wiring is OK, replace control unit.