How to Replace a Fuel Pump Relay

The fuel pump relay on your car is a special switch that controls the flow of electrical current between the ignition switch and the fuel pump. Electro-mechanical relays have movable contact points and small coils, which are a common source of problems after years of use. Once the points burn or the coil breaks, the incoming voltage to the fuel pump is blocked and your car engine cannot start. However, fuel pump relays are easy to replace.

Things You'll Need

  • Exact fuel pump relay replacement
  • Nose or rib joint pliers if necessary
  • Buy the exact fuel pump relay replacement for your car vehicle make and model. You can find one at most auto parts stores in your area. If your particular relay is hard to find, go to the parts department of your local dealer.

  • Find the fuel pump relay. Depending on your vehicle make and model, you can find it almost anywhere. Common places are under the instrument panel and engine compartment. However, some may be found under the seat and even the trunk. Check the fuse box under the driver side of the dashboard. In the engine compartment, look for the relay inside a junction block (a single housing for several relays), near the firewall or strut tower. The fuel pump relay is a small plastic cube, about 2 by 2 by 1 inces inch in size. Most of the time, the relay is marked for easy identification.

  • Pull the fuel pump relay off its mounting base once you find it. Sometimes you can unplug it straight out of its mounting base or electrical connector. However, if the relay is mounted between two relays or other components and you cannot get a good hold on it, you may use nose or rib joint pliers.

  • Compare the new relay to the old one and make sure the connecting prongs match. Plug the relay in place and make sure it sits properly.

  • Start the engine and make sure the new fuel pump relay is working properly.