How to Install a Fuel Pump Relay

What You'll Need
Fuel Pump Relay
Flat head Screwdriver
8-ga wire
30-amp fuse
30-amp fuse holder
Insulation tape
Wire stripper
Nose pliers
Zip ties
Ring connector

A Fuel pump relay is a setup used in automobiles to maintain a consistent voltage supply to the engine. This consistency ensures a steady flow of fuel to the engine. An automobile can have a long life if the engine receives consistent flow of fuel and air, especially during high speed driving. Thus, installing a fuel pump relay will increase the life of your vehicle.

Step by Step Procedure

Step 1 – Prepare the Vehicle

The power supply form the vehicle’s battery needs to be terminated as a precautionary measure for this job. It is enough if you disconnect the negative terminal of your car’s battery alone; however, it is safer to disconnect the positive terminal as well.

Step 2 – Check the Engine

Unscrew the hood portion of the fuse box in your car’s engine compartment. Most cars may contain a diagram showing the position of fuses and relays on the lid or on the side wall of the fuse box. See if the engine has a fuel pump relay or not (the fuel pump relay is a cube shape connected like an electric plug). If you cannot locate the relay get the help of your usual mechanic. If you do not have a relay directly go to the fourth step.

Step 3 – Remove Old Relay

If there is a worn out old relay, remove it with a flat head screwdriver.

Step 4 – Purchase the Correct Relay

Go to the automobile spares outlet or the spares outlet of your car’s manufacturer and purchase the correct fuel pump relay for your car. If you have the removed relay, you can use it as a sample.

Step 5 – Preparing to Install

If you did not have a relay at all, you have to do the wiring as mentioned in this step, else you may move directly to the sixth step. For wiring, remove the hose in the fuel tank and lift the valve off. Remove the wiring harness by moving the locking latch down.

Attach a connector to the cable of the car’s battery and connect the 8-ga wire to it. Connect the other end of the 8-ga wire to the 30-amp fuse holder. Set this wire along with the bundle of wires along the firewall with zip ties. Insert the wire through a hole in the driver’s side of the firewall. Run the wire under the carpeting and bring it to the fuel pump housing side. Join the wire to the 87 terminal of the relay.

Step 6 – Connect the Relay

Join the black wire from the fuel pump to the 30 terminal of the relay and the black wire from the wiring harness to the 86 terminal of the relay. Join one more wire to the 85 terminal of the relay which acts as the ground wire. Screw the relay to the body tightly.

Step 7 – Check

Connect the cables to the battery of the car and check your work by starting the engine.