How To Wire A Relay For Fuel Pump

This wire will connect to the 87 terminal position.

How to wire a relay for fuel pump. If you are using a fuel injection system then you need to use the fuel pump signal as the trigger for the relay. They are usually labeled 30 85 86 and 87. This 12v wire will now energize the relay to turn on. The other side of your fuse device goes directly to the battery terminal.

Wiring in the fuel pump relay. The fuel pump relay may be faulty or have a loose connection if it s developed any rust or corrosion on the prongs. Wire pin 85 of the relay to the 12v supply wire from the stock ecu that you just cut. Join one more wire to the 85 terminal of the relay which acts as the ground wire.

Wire which leads inside the vechicle to the ign spade lug connector on the fuse box. So now instead of the stock ecu energizing the fuel pump it will energize this relay. Listen for the fuel pump to activate. 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.

Turn the key on again and listen for the fuel pump relay to buzz or click. The 30 position on the relay will go to a fusible link in line fuse or circuit breaker. Hold the relay upside down so the prongs point up and firmly scrape them with a wire brush. Scrape off as much corrosion as you re able to so the relay has a solid connection when you plug it back in.

Wire the oil pressure switch s s terminal to the ignition cranking start circuit to provide fuel pump pressure during engine cranking and or via a dash mounted toggle switch to prime empty. Electric fuel pump relay wiring diagram electric fuel pump relay wiring collection wiring diagram rh visithoustontexas org electric fuel pump parts holley electric fuel pump diagram. The diagram is color coded per circuit and only a few things may need to be said. For carbureted engines you can connect the relay to a switched ignition source must have power in both start and run key positions or you can simply wire in a manual switch.

Turn off the ignition after the fuel pump stops making noise. So use a larger gauge wire for lower voltage drop. Basic safe electric fuel pump wiring diagram this is the basic wiring diagram for safe electric fuel pump wiring. You may have to have an additional person touch the fuel pump relay to feel the buzz or clicking motion.

Fuel pump wiring for the red circuit is generally going to carry a much higher current than the relay. The relay should have 4 pins on it. You need to run at least a 10 ga.