Fuel Pump Control Unit: Testing and Inspection

Check operation of fuel transfer pump before performing this test procedure. See FUEL TRANSFER PUMP in this section.

1. Make sure there is enough fuel in the tank for the transfer pump to operate (1/3 full minimum is recommended).

2. Disconnect control unit harness connector, and turn the ignition "ON".

3. Check for battery voltage at the harness side connector terminal with the Black/White wire.

^ Should have battery voltage. If not, repair wiring between control unit and ignition switch.

4. Check for continuity to ground at the terminal with the solid black wire.

^ Should have continuity. If not, repair open in wiring.

5. Check for continuity to ground at the terminal with the Black/Green wire.

^ Should NOT have continuity. If continuity exists, Re-connect control unit and continue testing.

Checking Transfer Pump Switch And Control Unit:

6. Remove rear seat cushion, disconnect float switch connector (see illustration) and jumper between the Black/Green wire and ground (Black wire).

^ Transfer pump should run without jumper wire, and turn off when jumper wire is connected. If pump runs with jumper wire connected, check B/G wire for open between float switch and control unit. If pump will not run at all, check for short to ground in B/G wire

7. If no wiring problems have been found at this point, disconnect electrical connector at transfer pump, and check for voltage at the Black/Yellow wire.

^ Should have battery voltage. If not, check Black/Yellow wire for open circuit.

If no wiring problems are found, replace transfer pump control unit.