What color is the power wire on a fuel pump (Full Guide)

The most common power wire color is red. But that does not mean that it is an industry standard. A vehicle manufacturer can have different color wires attached to their vehicle’s fuel pump. If you are not sure if the red wire on your vehicle’s fuel pump is the power wire, you can always consult your vehicle’s manual. Also, take your vehicle to a mechanic. They will know which wire is the power wire.

What color is the power wire on a fuel pump?

Most vehicle manufacturers choose to use red wires for power wires. But there is no industry standard that says all power wires are red.

It is up to the manufacturer. So that means each vehicle could have its own color scheme when it comes to wiring colors.

If you look at your vehicle’s fuel pump and do not see any red wires, then you will have to consult your vehicle manual and see which one is the power wire.

You can also take an electric measuring tool and use the tool to discover which wire connects to the battery.

Some car manufacturers use gray, orange, or purple wires, so we understand if finding the power wire on your vehicle’s fuel pump becomes difficult. 

If you cannot determine which wires allow electricity to flow from the battery to the fuel pump, then you can test the fuel pump to see if there is a charge flowing into it.

What tool can I use to test if there is power going to the fuel pump?

You can test if there is a charge flowing through the wiring by attaching a specialized tool to the terminals of the fuel pump.

Using any tool to measure the electricity coming from the wires attached to a fuel pump may be the best way to find which wire is the power wire. The tool you will need to determine if a wire is a power wire is the multimeter.

A digital multimeter is a measuring tool that evaluates voltage, amps, and resistance. Anyone who works with wiring or electrical equipment will use their industry’s version of a digital multimeter on a regular basis. 

How to use the digital multimeter to find the power wire on a fuel pump.

It is very easy to use a multimeter to find the power wire. If you have never done it before, it will only take you one or two times to understand what to do.

The first thing you must do is locate the fuel pump. It will either be inside or next to the fuel tank. Once you find the fuel pump, locate any of the wires that are coming from the fuel pump. 

One thing to note is that the wire that provides electricity to the fuel pump will look much thicker than any of the other surrounding wires.

Take the negative and positive wires from the multimeter and connect each one to the positive and negative terminals of the fuel pump. 

Place the key into the ignition but do not turn on the engine. Just turn the key so that the battery is on. The multimeter should display a voltage reading of 0.1 to 0.5. 

Fuel pump issues from bad wiring

When a vehicle fuel pump does not have its power wires connected correctly, it will not operate the right way. There are several signs that will appear when the fuel pump’s wiring is not working correctly.

● The is not functioning the right way. It can no longer conduct the correct amount of electricity to power the fuel pump. This issue usually happens due to age. As a vehicle gets older, many of its parts don’t work as efficiently as they once did. 

Messed-up wires can also be the result of an accident. When reassembling the engine, the mechanic may not have seen the state of the wire and did not replace it when it needed replacing.

● The wire is not connected at all. A disconnected wire doesn’t happen often, but it can be the result of improper installation and rough handling. This may happen after getting a fuel pump uninstalled and then cleaned. 

When the pump is being reinstalled, the mechanic might not connect the wires the right way. These unsafe wires will disconnect completely as the driver drives their vehicle. 

How would a vehicle owner know if the fuel pump is not connected to the battery at all? 

The engine will take multiple attempts to start or will not start at all. The vehicle will also not be able to accelerate as fast as it should when pressing down on the gas pedal. 

● The check engine light is on. The engine in a vehicle has multiple sensors that communicate with each other. They can adjust their own activities based on the information they get from other sensors.

Now, the check engine light will turn on for many reasons, so suddenly appearing does not always mean that there is an issue with the wiring on a fuel pump. So go to your mechanic when the check engine light goes on to find out why it is on.

When the fuel pump wiring is not working correctly, the vehicle’s internal system will notice and signal for the check engine light to turn on.

Once the check engine light turns on, you must take your vehicle to the mechanic. They can assess the problem and communicate with the vehicle diagnostic system.

● The vehicle will need more power and time to accelerate. When the fuel pump is not receiving the power it needs to operate correctly, it will not be able to deliver the right amount of fuel to the engine.

This will cause issues in the combustion chamber as the fuel to air mixture inside the piston chamber will be off.


Each vehicle can have different colors for the power wire on a fuel pump. Most manufacturers will use red and black, but others will use gray, orange, or purple. If you cannot find the power wire, you can use a multimeter tool to measure if there is a charge flowing into the fuel pump.

  • Eric Williams

    I'm the founder of Daily Car Tips. I wrote articles in the automotive industry for more than 10 years, published in USA and Europe. I love sharing my knowledge and insights with fellow enthusiasts. Join me on this journey as we explore the exciting world of cars together!

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