1987 Chevy Truck Fuel Pump Wiring Diagram

When it comes to wiring diagrams for your 1987 Chevy Truck’s fuel pump, it might be overwhelming to find the right resources online. However, knowing the right diagram is essential for your truck’s proper functioning.

Understanding the Fuel Pump Wiring Diagram

The wiring diagram for your Chevy truck’s fuel pump provides a detailed map of the electrical connections that should be made to ensure that everything works as it should. The diagram shows the power supply to the fuel pump, the ground wire, and the signal wire that connects to the fuel gauge.

For an ’87 Chevy truck, the fuel pump wiring diagram generally consists of four wires. Two of these wires are for the fuel gauge, one is for power, and the last one is the ground wire. Making sure that these wires are connected correctly is essential to ensure that the fuel pump works properly.

Power Wire Connection

The power wire is responsible for connecting the fuel pump to a power source. This wire is usually colored red and should be connected to a reliable power source. It is recommended to use a relay that is triggered by a switch to ensure that the pump is only powered when necessary.

Additionally, it is essential to make sure that the circuit fuse is compatible with the amperage required by the fuel pump. The recommended fuse amperage for an ’87 Chevy truck fuel pump is 20 amps.

Ground Wire Connection

The ground wire is responsible for completing the circuit, allowing the fuel pump to function correctly. This wire is usually colored black and should be connected to a reliable grounding source.

It is important to note that the ground wire should be connected directly to the body of the truck, and not through any connectors or electrical devices. This ensures that the fuel pump receives consistent grounding and functions properly.

Signal Wire Connection

The signal wire is responsible for providing the fuel gauge with the information it needs to display the fuel level. This wire is usually colored purple and should be connected to the fuel gauge in the dashboard.

It is important to note that the fuel gauge must be calibrated correctly to ensure that the displayed fuel level is accurate. Calibration is achieved by adjusting the resistance of the fuel gauge and should be done by a qualified technician.


Question Answer
What happens if the fuel pump wiring is incorrect? If the wiring is incorrect, the fuel pump may not receive power, may not receive a signal to start, or may not receive ground. This can result in the fuel pump failing to work, leading to your truck not starting, or stalling while in operation.
Can I replace the fuel pump wiring myself? Replacing the wiring yourself can be done, but it is recommended that you have some experience with automotive electrical systems. If you are unsure, it is best to have the wiring replaced by a professional mechanic.
How do I know if my fuel pump needs to be replaced? Common signs of a failing fuel pump include difficulty starting the engine, the engine stalling while in operation, and reduced fuel efficiency. If you suspect that your fuel pump is failing, it is essential that you have it checked by a qualified mechanic.
How often should I replace my fuel pump? The lifespan of a fuel pump depends on several factors, including the type of fuel used, how often you drive, and the age of your truck. Generally, it is recommended to replace your fuel pump every 100,000 miles.

Understanding the wiring diagram for your Chevy truck’s fuel pump is essential to ensure that everything works as it should, and your truck runs smoothly. If you are unsure about the wiring, it is recommended that you consult with a qualified mechanic to ensure that everything is connected correctly and functions as it should.