How to Replace a Fuel Pump Wiring Harness

A detailed step-by-step guide for how to connect the new wiring harness that may be supplied with a new fuel pump.




Hi everyone. Welcome to Delphi’s How-To Series Videos. I’m Clay Pennington, Product Specialist here at Delphi Products and Services. In this video we’ll show you how to replace the old fuel pump wire harness or pigtail with the new one that may be supplied with your kit. Wire harness is essential to make sure your new fuel pump will operate properly. We always put safety first, so make sure you wear your safety glasses and make sure you have a fire extinguisher on hand.

Start by disconnecting the battery first, and then disconnecting the wire harness from the fuel pump. Luckily for demonstration purposes, we have a harness that came off the vehicle. We can do this on the bench to show you.

You’ll need to remove about a foot of the wire harness and the conduit from the old wire harness before you start cutting. Make sure you’re dealing with the one four wire connector for the fuel pump module, and not the fuel pump’s fuel pressure sensor connector.

Start by cutting the first wire from the connector about two inches away from the connector, and then stagger the rest of your cuts about an inch and a half. Now I have the old pigtail removed, and we can move on to start replacing it with the new one.

If the wire colors aren’t identical to the car and the new connector, refer to the wiring diagram that’s also supplied with the kit.

Once you’re determined the wire pattern and the wire colors you’ll have to connect to, you can then start stripping, cutting the new connector to match the old wiring harness.

Once you have your wires cut and staggered, you can then move on to stripping the wires before putting on the connectors.

Now it’s time to start crimping. The connectors are two different sizes, for the larger wires for the ground and the supply for the fuel pump, and the smaller ones for the fuel stemming unit.

Make sure you crimp them firmly, and make sure you don’t get any of the insulation trapped in between the electrical connective crimp.

To heat shrink these connectors, you want to make sure you use a heat gun, not any open flame source. Also, be sure to keep it away from any fuel spills that may have occurred. Make sure you got that fire extinguisher on hand.

Heat gun works pretty good, as long as you have a nice, high quality heat gun, and it’ll be completely finished when you see the glue start coming out of the connector, itself, giving a good seal.

Now you’ve got a finished product, staggered connections, nice weathertight seals. Finish up by re-inserting it into the conduit, wrapping it up with any electrical tape that you need, and you’re all set.

You’re all done. Now you can be confident that your new fuel pump will have a secure connection for the life of the vehicle.

Thanks for watching. Be sure to check out our other Delphi How-To Series videos that help save you time in your shop every day.