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Home >> Oldsmobile >> 1990 >> Custom Cruiser >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Relays >> Fuel Pump Relay
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Fuel Pump Relay

  1. Disconnect fuel pump relay. See SYSTEM & COMPONENT TESTING article. Apply battery voltage and ground to fuel pump relay winding terminals. To identify fuel pump relay terminals, see appropriate wiring diagram in WIRING DIAGRAMS.
  2. Using an ohmmeter, check continuity between fuel pump relay power and fuel pump relay drive terminals. Continuity should exist. If continuity does not exist, fuel pump relay is defective.
  3. To by-pass fuel pump relay on-vehicle (fuel pump not operating), turn ignition off. Disconnect fuel pump relay connector. Using a fused jumper wire, connect fuel pump test connector to positive side of battery. Fuel pump should run.
  4. If fuel pump runs, check for faulty connections to relay or replace defective relay. To locate fuel pump test connector, see the SYSTEM & COMPONENT TESTING article in this section.
Fig 1: Typical Fuel Pump Relay Schematic
G90D13212Courtesy of GENERAL MOTORS CORP.