1986 Fuel Pump Relay Location: Complete Guide for Ford, Buick, Volkswagen, and More

If you own a 1986 vehicle and are dealing with fuel delivery issues, the fuel pump relay is often the first component to check. The location of the fuel pump relay on a 1986 model varies significantly depending on the make and model. For most 1986 Ford trucks and cars, the fuel pump relay is located under the hood on the driver's side inner fender or firewall, often with a green base. For 1986 Buick Century models, it is typically found at the firewall under the hood. For 1986 Volkswagen Jetta models, the relay is inside the interior fuse box. For 1986 Volvo 240 models, it is located on the passenger side under the glovebox. This guide breaks down the exact locations, testing procedures, and common symptoms for each popular 1986 model.

Why the Fuel Pump Relay Matters

The fuel pump relay controls power to the fuel pump. When you turn the key to the "on" position, the engine computer (ECU) grounds the relay for about two seconds to prime the fuel system, then ungrounds it until the engine starts. Once the engine is running above 400 RPM, the computer grounds the relay again to keep the pump running continuously . If the relay fails, the fuel pump may not run at all, or it may run continuously even after the engine is off.

1986 Ford Ranger Fuel Pump Relay Location

For the 1986 Ford Ranger, the fuel pump relay is located on the inner fender in the engine bay. It has a distinctive green base that makes it easy to identify . The relay is controlled by the engine computer, which grounds it to activate the fuel pump.

Key details for the 1986 Ranger:

  • The relay is typically found on the driver's side inner fender
  • It has a green plastic base
  • The computer grounds the relay through a blue/orange wire that also connects to the OBD1 test connector
  • Two fuel pump system: The 1986 Ranger uses two fuel pumps – a low-pressure lift pump inside the fuel tank, and a high-pressure pump mounted on the frame rail under the driver's seat area

If you need to test the relay, you can find the OBD1 connector in the engine bay (usually on the main wiring harness near the firewall on the passenger side). The "Fuel Pump" slot in this connector is the ground wire for the relay. By grounding that slot, you can manually activate the fuel pump with the key on .

1986 Ford F-150 and F-350 Fuel Pump Relay Location

For 1986 Ford F-150 and F-350 trucks, the fuel pump relay is located on the front left firewall under the hood, almost directly under the hood hinge . The EEC relay is found right next to the EEC control unit under the dash on the right side of the steering column .

Wiring for the 1986 F-Series:

  • The red wire supplies 12V power from the EEC relay
  • The yellow wire is the common connection
  • The brown wire is the output to the fuel pump
  • The tan/light green wire goes to the EEC computer and to pin 6 of the test connector

You can ground pin 6 of the test connector to manually turn on the fuel pumps for testing with the key in the "on" position .

1986 Ford Mustang Fuel Pump Relay Location

On the 1986 Ford Mustang, the fuel pump relay is typically found in the under-hood fuse box, usually near the battery or firewall . Look for a rectangular or square-shaped component with four to five pins. It is often larger than standard fuses and may have a distinct color or shape. The relay is usually marked as "FP" or "Fuel Pump" on the fuse box cover diagram .

Testing method for the Mustang:

  • Swap the fuel pump relay with a similar relay (such as the horn relay) to see if the fuel pump activates
  • Use a multimeter to check for continuity across the relay terminals
  • Check for 12V at the power input terminal (terminal 30)
  • The relay coil should have 40-80 ohms of resistance between terminals 30 and 87 when energized

1986 Buick Century 3.8 Fuel Pump Relay Location

For the 1986 Buick Century with a 3.8L engine, the fuel pump relay is located at the firewall under the hood . According to the Haynes manual for 1985-1995 Buick/Oldsmobile/Pontiac front-wheel-drive vehicles, the fuel pump relay is item #3 in the emission control component location diagram, positioned at the firewall .

Important note: The fuel pump test connector (C8) is located at the driver's side front of the car, also under the hood, next to the fuel vapor canister solenoid . The fuse box for this model is located inside the glove compartment.

1986 Volkswagen Jetta Fuel Pump Relay Location

The 1986 Volkswagen Jetta has two different fuse boxes where the fuel pump relay can be located :

Interior Fuse Box (Type 1):

  • The fuel pump relay is listed as Relay R2
  • It may also serve as the intake pipe heater relay or glow plug relay
  • The fuel pump fuse is a 15A ATO fuse (type No. 5)

Interior Fuse Box (Type 2):

  • The fuel pump fuse is a 20A ATO fuse (type No. 18)
  • It also protects the heated oxygen sensor control module

Common causes of fuel pump relay failure in the Jetta:

  • Current overload from the fuel pump drawing too much power
  • Short circuits in the electrical system
  • Worn internal components due to age and vibration

1986 Volvo 240 Fuel Pump Relay Location

For the 1986 Volvo 240, the fuel pump relay is located on the passenger side under the glovebox . The relay is white in color and sits above the felt panel in the glovebox area .

Important tip: If you are replacing the fuel pump relay because it burned up, check that the in-tank pump is working. If the in-tank pump has failed, the main pump will overheat and damage the relay .

1986 Mercedes-Benz 560SL Fuel Pump Relay Location

For the 1986 Mercedes-Benz 560SL, the fuel pump relay is located behind the glovebox, against the firewall . To access it:

  1. Remove the inner part of the glovebox (the "box" itself, not the lid or cover)
  2. Look for the relays against the firewall
  3. The fuel pump relay is a black box, located to the far left or right behind the idle speed relay
  4. You may need to remove the idle speed relay first to access the fuel pump relay

Common Symptoms of a Bad Fuel Pump Relay

Regardless of the vehicle make and model, a failing fuel pump relay typically shows these symptoms:

  1. Engine cranks but won't start – The most common symptom, as the fuel pump isn't receiving power
  2. Fuel pump runs continuously – The relay is stuck closed, keeping the pump running even after the engine is off
  3. Intermittent starting issues – The relay works sometimes but fails at other times
  4. No fuel pump noise when key is turned on – You should hear a 2-second hum when you turn the key to the "on" position
  5. Loss of power under load – The fuel pump may not be getting full voltage through a failing relay

How to Test a Fuel Pump Relay

Step 1: Listen for the pump
Turn the key to the "on" position (don't start the engine). You should hear the fuel pump run for about 2 seconds. If you don't hear anything, the relay may be bad.

Step 2: Check for voltage
Use a multimeter to check for 12V at the relay's power input terminal. Battery voltage should be between 12.3 and 12.8 volts with the key on and engine off .

Step 3: Swap the relay
If you have a similar relay in the fuse box (like the horn relay), swap them. If the fuel pump starts working with the swapped relay, the original relay is bad .

Step 4: Check the inertia switch
On Ford vehicles, the inertia switch is located in the passenger footwell, above the carpet under the glovebox. It has a red button on top. Test voltage at this switch – it should match battery voltage. If voltage is lower than 10V, there is a corroded connection somewhere between the battery and the inertia switch .

Why Buy KEMSO Fuel Pump?

If you have determined that your fuel pump needs replacement, consider the KEMSO brand for your repair. KEMSO fuel pumps are high-performance, OEM replacement parts designed to meet or exceed original equipment specifications. Each pump comes with a lifetime warranty, giving you confidence that your repair will last.

KEMSO offers fuel pumps for a wide range of vehicles, including cars, motorcycles, ATVs, and watercraft. Their products are built to deliver reliable performance, whether you are driving a 1986 Ford Ranger, a 1986 Buick Century, or a 1986 Volkswagen Jetta. With a commitment to quality and customer satisfaction, KEMSO ensures that you get the right part for your vehicle.

Visit their website to find the correct fuel pump for your 1986 vehicle: https://www.kemsoracing.com/

Final Thoughts

Finding the 1986 fuel pump relay location on your vehicle is the first step to diagnosing fuel delivery problems. Whether you drive a Ford, Buick, Volkswagen, Volvo, or Mercedes-Benz, the relay is usually accessible with basic tools. Always check the relay, fuse, and inertia switch before replacing the fuel pump itself. If the pump does need replacement, choose a reliable brand like KEMSO to ensure long-lasting performance. For more information on fuel pump options, visit https://www.kemsoracing.com/.


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