Fuel Pump Relay Wiring Diagram (Automatic Trans. Only)

Fuel Pump Relay Wiring Diagram (1994 Chevy Pickup 4.3L, 5.0L, 5.7L)

NOTE: The illlustrations and info in this page apply only to 1994 Chevrolet/GMC pickups with a 4.3L, 5.0L or a 5.7L engine. For the 1993 fuel pump wiring diagram, check out the following article:

  1. 1993 Fuel Pump Circuit Tests (GM 4.3L, 5.0L, 5.7L).

Fuel Pump Relay Diagnostic/Troubleshooting Notes:

  1. FP relay terminal A (ORG wire):
    1. Should have 10 to 12 Volts DC with Key On Engine Cranking or Key On Engine Running (KOER).
    2. This voltage comes from the GRY inline fusible link located in the engine compartment junction block.
  2. FP relay terminal E (GRY wire):
    1. Should have 10 to 12 Volts DC when the engine is being cranked and relay has activated.
  3. FP relay terminal D (BLK/WHT wire):
    1. Should have ground all of the time.
  4. FP relay terminal F (DK GRN/WHT wire):
    1. Power supplied by the PCM to the FP relay coil to activate the relay.

Fuel Pump Relay Wiring Diagram (Manual Trans Only)

Fuel Pump Relay Wiring Diagram (1994 Chevy Pickup 4.3L, 5.0L, 5.7L)

Fuel Pump Relay Diagnostic/Troubleshooting Notes:

  1. FP relay terminal A (ORG wire):
    1. Should have 10 to 12 Volts DC with Key On Engine Cranking or Key On Engine Running (KOER).
    2. This voltage comes from the GRY inline fusible link located in the engine compartment junction block.
  2. FP relay terminal E (GRY wire):
    1. Should have 10 to 12 Volts DC when the engine is being cranked and relay has activated.
  3. FP relay terminal D (BLK/WHT wire):
    1. Should have ground all of the time.
  4. FP relay terminal F (DK GRN/WHT wire):
    1. Power supplied by the PCM to the FP relay coil to activate the relay.

Fuel Pump Wiring Diagram

Fuel Pump Wiring Diagram (1994 Chevy Pickup 4.3L, 5.0L, 5.7L)

Fuel Pump Troubleshooting Notes:

  1. Oil pressure switch:
    1. If the fuel pump relay fails, what usually happens is that the oil pressure switch feeds power to the fuel pump and gets the engine started and keeps it running.
    2. When this happens, the engine will crank till the oil pressure gets up and the oil pressure switch closes.

Location Of The Fuel Pump Relay Components

Fuel Pump Units Wiring Diagram -Dual Tank (1994 Chevy Pickup 4.3L, 5.0L, 5.7L)
ff    Fuel pump in-line fuse -20 Amp.
ff    Junction block.
ff    Fuel pump relay.