Since it is one part of your vehicle that runs constantly, the fuel pump significantly impacts your engine and can face lower performance after a time because of wear. The fuel used, the cleanliness of the fuel tank, and the level of fuel kept inside the fuel tank all affect the fuel pump’s lifespan.
If the fuel is of poor quality, the in-tank fuel pump strainer will clog and could discharge unfiltered fuel to the fuel pump motor. Here, the fuel pump loses the ability to supply fuel because of clogging in the impeller blades and damage to the impeller surface.
You’ll need to replace the fuel pump strainer at predetermined intervals to prevent fuel pump damage. If your Ford, GM, or another brand of vehicle is already experiencing vehicle stalling. You may need to replace the electrical contacts or the fuel pump.
So, to ensure proper wiring harness connections, you need to know the manufacturer color coding fuel pump wires’ color codes. These aren’t too difficult, yet it helps to have the wire color codes for the fuel pump wires to refer to, or you could burn out the vehicle’s fuel pump or have an error in your instrument cluster.
Typically, the electrical fuel pump wires’ color codes comprise gray, black, and white stripe, purple, and black and signify power to the fuel pump, a ground connection, power to your fuel gauge, and ground to the fuel level sender unit.
As each vehicle manufacturer may have subtle variations, you can learn more about what’s what with these color codes. By the end, with simple tools, a self-test connector, and a test light, you can change what you need and ensure your power wires are where they should be, and you won’t cause a short. (Read Can You Drive With 35 Window Tint At Night)
Why You Need A Fuel Pump Wire Code?
The fuel pump is an essential part of the fuel injection system in every vehicle; its failure can cause many problems, including engine knocking.
It’s not a bad idea to DIY your fuel pump system to address electrical issues, but before you mess with the wires, ensure sure you understand what each one is for.
The fuel pump typically has four wires;
- A ground which is a black wire/ pink wire
- A yellow-and-white wire for fuel-level communication
- The power cable for the pump is a grey or orange wire.
- A dark blue wire sends warnings when the fuel level is low, or the fuel pump is experiencing other issues.
The fuel gauge wire reads 5V current when you turn on your car.
Here is an overview of the task of each wire:
- Fuel Pump Wire: Although there could be various colors, grey and orange are found in a Ford or GM vehicle. The actual fuel pump wire is typically either one of these colors.
- Ground Wire: The ground wire is typically black (with a white stripe) or plain white without stripes on Ford and GM motors.
- Ignition/ Starter: While mainly black, some autos’ fuel pump ignition or starter is an orange wire. This wire powers a grounded sending module in the fuel pump relay when the car is started.
- Fuel Gauge / Fuel Level Wire: The fuel level wire transmits the amount of fuel still in the tank to the ECU; the fuel gauge on your dashboard receives the signal from this wire. Yellow with a white strip or purple is the coating on this wire.
What are GM Fuel Pump Wires Color Codes?
If you are doing any repair work on a GM truck fuel pump. The fuel pump assembly may have the pump and sender in one unit. The difficulty comes when you confuse wire color codes when your vehicle handbook doesn’t specify any color codes.
Finding which color wire goes where wastes time and could cause further issues. Depending on the vehicle type and year, your wiring harness may have different colors than your fuel pump.
To connect a new fuel pump, you’d need to cut the old wiring harness by the old electrical connector. Here, you need to add in the new wires. So, when replacing electrical connectors for the fuel pump, it’s vital to know the color coding so you can do the job right the first time.
The fuel pump wiring harness has a color code, and each wire signifies a current flow path or a ground path for electricity flow to a fuel pump module part.
The typical GM fuel pump wires’ color codes are:
- Gray is the power to the fuel pump from your fuel pump relay when in start mode
- Black and white strip wire is a ground connection to your fuel pump
- A purple wire on a GM fuel pump module is the power signal to the fuel level sending unit
- A black wire is a ground connection for the fuel level sending unit.
If the vehicle wiring harness color doesn’t match the fuel pump wires’ color codes, you may need to use a multimeter to determine which wires are powered and which are grounded.
What Happens If I Wire A Fuel Pump Relay Wrong?
If the fuel pump is wired wrongly when replacing the fuel pump on your GM vehicle, the fuel pump won’t receive power because the power supply wire from the fuel pump relay won’t be connected to the fuel pump. As a result, the vehicle won’t start, and the fuel pump won’t pump fuel into the engine.
The fuel level indication on the dashboard will not represent the fuel level in the fuel tank if the fuel level sender unit is wired incorrectly. Even if the fuel tank is wholly or partially filled, the indicator may show “zero fuel.” (Learn How to Clean Car Battery Corrosion Without Removing)
Ford Truck Owners Fuel Pump Wires Color Codes [F150, F250 & F350]
Before making any do-it-yourself wiring repairs, you should know the color codes for the Ford fuel pump wires. It’s challenging to connect the wires without a technical understanding of the color scheme and the choice between a single tank and a dual tank.
1. F150 Fuel Pump Wires Color Codes For Single Fuel Tank
All F150 models use the same fuel pumps, so here are the F150 wiring color codes:
- Pink/Black: Feeds power to the pump motor inertia switch with a +12-volt supply.
- Black: Supplies a ground connection. The circuit controls and safeguards the fuel pump by receiving instructions from the power-train control module (PCM) through a 20 amp fuse and fuel pump relay.
- Yellow / White and Black / Orange: The fuel level is measured by the fuel pump sending module. Also, it transmits signals for dash display fuel levels. An F150’s fuel pump wiring harness uses two dedicated cables for the sending unit. A yellow/white cable signals the instrument cluster for the fuel level, while a black / orange cable is the ground.
Tip: Aftermarket fuel pump wiring color codes differ, so you’ll need to double-check how they marry up to your vehicle’s fuel injection system components around the fuel pump. (Read Can I Use 5W 30 Instead Of 5W 40)
2. F250 Single Ford Fuel Pump Wires Color Codes
The Ford F250 has options for the dual and single fuel tank. The single fuel tank is very similar to that of the larger option of the F250, including fuel pump wires color codes.
Check the above color codes to rewire a Ford F150 or F250 fuel pump.
3. F350 Single Fuel Tank Ford Fuel Pump Wires Color Codes
Four wires total (two for the fuel level sender module) are on the F350 single fuel tank, as explained below.
- Black-Striped Pink: This wire carries 12 volts of power from the inertia switch to the pump and can heat during engine cranking to start.
- Orange: An orange cable is the ground.
- Yellow/White: This passes power to the instrument cluster to show fuel levels.
- Black/Orange: The ground wire for the sending unit’s circuit. A relay unit pump relay triggers the on and off from signal sent from the selector switch on the PCM as the engine is started.
4. Ford Fuel Pump Wires Color Codes for Dual Fuel Tank Vehicles
In addition to single-fuel tanks, Ford trucks also offer twin-fuel tanks. Due to the vehicle’s dual fuel tanks, there are also two fuel pumps. You can choose between any of the two fuel pumps using the selector switch on the dashboard.
Without looking for a wiring diagram, this is what you need to rewire your fuel pump because the dual fuel tank system is complex.
Fuel Pump Relay
The unit has four colored wires, as described below.
- Red Wire: The red wire passes power to the relay coil from the PCM.
- Yellow: Connects to a 20-amp fuse.
- Deep Green/Yellow: When your engine is working, a deep green/yellow wire gets 12 volts from an open relay contact.
- Light Blue/Orange: A PCM relay control wire sends signals to a relay coil to deactivate or activate it.
Fuel Tanks Selector Switch
The driver’s side of the vehicle’s cabin houses this selector switch. Six cables are used for operation, thus enabling you to select between the front or rear pump for the front or rear tank to be used. (Read No Coolant In Reservoir – What To Do)
- Red: Passes power to the front tank.
- Brown/White: Passes power to the rear tank pump.
- Yellow/Light Blue: Powers the rear tank’s sender module.
- Dark Blue/Yellow: Powers the front tank’s sender unit.
- Yellow/White: Connects the instrument cluster to front and rear sender units according to the chosen tank.
- Red/Yellow: The cable gets +12 volts from the fuel pump relay and is connected to the inertia switch.
Fuel Pump Color Code For Front Tank
Four wires connect the fuel pump and sender unit:
- Red: Passes power to front tank and front pump.
- Orange: helps the pump ground in closing the circuit.
- Dark Blue/Yellow: Connects the instrument cluster to the fuel level sender module.
- Black: A ground wire that facilitates a return passage for the sender unit current.
Fuel Pump Wire Color Codes For Rear Tank
- Brown/White: Supplies +12 volts power wire using the same link as the front fuel pump.
- Orange: Ground for the brown/white cable.
- Yellow/Light Blue: Carries return signals from a fuel level sender module to your instrument cluster.
- Black: Offers ground to your yellow/light blue cable.
