How to Wire a Fuel Pump to a Toggle Switch (Steps With Photos)

There was a huge spike in car thefts last year, we went from 721,885 to 810,400 thefts. Learning how to wire an electric fuel pump to a toggle switch is one of the most powerful strategies to deter automobile thieves. This simple system will shut down your electric fuel pump, making it impossible for someone to steal your automobile.

Today we have a guest writer, Rafael Lizarraga (Rafiki) he’s been a stereo/ auto security installer for cars for the past 20 years and used this method a hundred times.

In general, here’s how to wire a fuel pump to a toggle switch:

  • Locate your fuel pump component and wiring and gain access to them. Examine the power of your fuel pump.
  • Connect the fuel pump cutoff switch to the fuel pump.
  • Your fuel pump wire should be cut and spliced. Your kill switch protects your car wiring by cutting electricity to your pump when necessary.

Fortunately, the steps on how to wire an electric fuel pump to a toggle switch are pretty straightforward and I will go through them in detail below.

What You Will Need

  • Single post relay
  • Inline fuse
  • Digital multimeter
  • Wire strippers
  • A kill switch kit

Tip: I highly recommend hiding the kill switch so that auto thieves won’t be able to steal your fuel pump.

Step 1: Locate and Access Your Fuel Pump

locating and accessing fuel pump
Video | ChrisFix

Find your vehicle’s electric fuel pump. Your fuel tank is the most likely spot. Loosen the filler cap from the fuel tank and place your ear near the nozzle. Make sure someone turns the ignition key from off to power. You can hear the gasoline pump click or buzz for two or three seconds after it turns on. If you’re certain the pump isn’t inside the tank, trace the fuel line from the tank to the engine until you find it.

Locate your fuel pump component and wiring and gain access to them. In accordance with your application, you may need to dismantle your back seats or reach your fuel pump through your trunk. It doesn’t matter how you get to your gasoline pump assembly. You’ll need to be able to get to the connector and then strip and cut the connections.

Step 2: Inspect Your Fuel Pump Power

You should check the voltage using your digital multimeter. Unplug the fuel pump harness and examine for switched current by grounding the black lead of your multimeter. Remember that you must have your ignition switched on for this to function.

inspecting fuel power with multimeter
Video | ChrisFix

Check if you can route the cables to the outside of the car through the floor. Drill a hole if necessary. Also, ensure there’s an adequate area for the switch assembly and wiring beneath the switch.

Step 3: Install Your Fuel Pump Kill Switch

Install the switch in your desired spot. To secure the switch in place, insert it from the back and tighten the ring nut on the switch body on the outer side. Make sure the on and off positions are correctly oriented, such as up is on and down is off.

This phase is simple and uncomplicated if you’ve purchased a complete kill switch kit. You might connect your fuel pump kill switch using a common single post automotive relay by following the circuit diagram for the fuel pump kill switch shown below.

fuel pump / switched power diagram
Video | ChrisFix

The above fuel pump kill switch wiring figure indicates how to modify any standard automobile relay. When you’ve finished installing your kill switch, you can turn off your gasoline pump at any moment.

The gasoline pump kill switch can then be hidden or stashed so that a thief cannot find it.

Step 4: Disconnect the Power Line to Your Fuel Pump

Using the wiring diagram above, trim and splice your fuel pump components. Your single post relay and kill switch safeguard your car wiring and shut electricity to your pump on command.

Double-check your wiring after installing your fuel pump kill switch to ensure that your pump does not turn off on its own.

blue wires
Video | ChrisFix

Although fast electrical connectors can be used, I highly suggest you solder your connections.

Never access the fuel pump component when installing a gasoline pump kill switch. Gas vapors or fumes can create a hazardous working environment. (1)

Handful Tips 

When performing this anti-theft strategy, there are a few crucial considerations to keep in mind. Here are just a few of these below: (2)

Tip 1: Use a Relay at All Times

It is not recommended you install a kill switch and have it sitting alone. Many three-prong toggle switches lack the necessary amp capacity, leading to electrical issues. These issues can lead to your switch melting or even catching fire. Rather than taking chances, always use an automotive relay and an appropriately graded kill switch.

Tip 2: Install an Inline Fuse

Implementing an inline fuse to your power cable is a crucial safety measure that keeps things safe in the event of an electrical disaster.

Tip 3: Utilize the Appropriate Wire Gauge

Employ automotive wire that is sturdy enough to withstand the voltage. An electrical fire might arise from using a thinner wire that cannot securely transmit voltage.

Tip 4: Keep your Fuel Pump Kill Switch Hidden

If you leave the kill switch in an easily accessible location, your installation will be useless. Mount or hide your switch somewhere safe and accessible only to you.

Take a look at some of our related articles below.

(1) hazardous working environment –
(2) anti-theft strategy –

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About Sam Orlovsky

b1d87d2ee85af3e51479df87928bdc88?s=90&d=mm&r=gCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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