Diagnose A Bad Fuel Pump Relay & Steps To Replace It

Posted on: 26 March 2015

The fuel pump relay is there to make sure your car has enough power to satisfy your fuel needs. The fuel pump relay does this by keeping a specific voltage, but this can fail. The following are signs that you have a bad fuel pump relay and a guide to replace it yourself.

Signs of A Bad Fuel Pump Relay

Symptoms to look out for:

  • Engine that cranks and sounds like it is going to start, but does not
  • Loss of power as your driving
  • Engine starts, but stops shortly after
  • Your car dies on you as if you don't have gasoline
  • No sound from your fuel pump, which is located in the back of your car. Usually sounds like a click when you try to turn on your car

You can talk to your auto care specialist to confirm your suspicions because some of these symptoms could also be related to a clogged fuel filter or bad fuel pump.

Replacing Your Fuel Pump Relay

You'll need the following:

  • Gloves and safety glasses
  • Owner's manual or your auto repair manual (you can purchase this if you don't have one in your local auto parts store)
  • New fuel pump relay
  • Flat head screwdriver

Follow the steps below to change your relay.

  1. Park your car in a leveled and safe place.
  2. Let your vehicle cool, so that it is safer to work on.
  3. Put your gloves and safety glasses on.
  4. Disconnect your car battery, just to be safe.
  5. Use your owner's manual to help you locate your fuse box inside your hood. Most fuse boxes are on the sidewall on the passenger side, under your hood.
  6. Unscrew the lid that's usually on top of the fuse box.
  7. The fuel pump relay is a cube-like electrical plug.
  8. Carefully remove your old relay using your flat head screwdriver.
  9. Start replacing your new fuel pump relay by connecting the black wire from the fuel pump to the 30 terminal of the relay.
  10. Connect the black wire from the wiring harness to the 86 terminal of your relay.
  11. Join the last wire to the 85 terminal of your relay.
  12. Screw in the fuel pump relay tightly, and close the lid.
  13. Reconnect your battery, and turn on your vehicle.

That is how simple it is to fix your fuel pump relay problem. But, remember you can talk to your auto parts/care specialist if you feel uncomfortable with any of the aforementioned steps.