1997 Jeep Grand Cherokee Fuel Pump Relay: Location, Testing, and Replacement Guide

If your 1997 Jeep Grand Cherokee is cranking but not starting, the fuel pump relay is one of the most common and easiest components to check before assuming the fuel pump itself has failed. The fuel pump relay is a small electrical switch located inside the Power Distribution Center (PDC) under the hood, and it controls power delivery to the fuel pump. A faulty relay can prevent the pump from running, leaving you stranded. The good news is that testing and replacing this relay is a straightforward job you can do at home with basic tools, often saving you a costly tow or unnecessary parts replacement.

How the Fuel Pump Relay Works in Your 1997 Grand Cherokee

The fuel pump relay is an essential part of the fuel delivery system. It acts as an electronic switch controlled by the Powertrain Control Module (PCM). When you turn the ignition key to the ON position, the PCM sends a ground signal to the relay, which then closes and allows battery voltage to flow to the fuel pump. The pump will run for approximately one second to prime the fuel system unless the engine is started or the starter motor is engaged .

Once the engine is running, voltage is supplied by the charging system, but the relay continues to keep the fuel pump powered as long as the engine is operating . The relay itself has five terminals, numbered 30, 85, 86, 87, and 87A. Terminal 30 is connected to battery voltage at all times. The PCM grounds the coil side of the relay through terminal 85, and terminal 86 supplies voltage to the coil side. When the relay is energized, terminal 87 connects to terminal 30, sending power to the fuel pump circuit. When de-energized, terminal 87A connects to terminal 30, which is the off position .

Where to Find the Fuel Pump Relay on a 1997 Jeep Grand Cherokee

The fuel pump relay is located inside the Power Distribution Center (PDC), which is the main fuse and relay box under the hood. On the 1997 Jeep Grand Cherokee, the PDC is a black plastic box typically found on the driver's side near the battery or the inner fender. To access the relay, simply unclip the cover of the PDC. The underside of the cover has a diagram or label that identifies the position of each relay and fuse.

According to the service manual and diagrams, the fuel pump relay is marked with the letter "C" in the PDC layout . The PDC also contains other important relays, including the Auto Shutdown (ASD) relay, starter motor relay, and transmission control relay. The fuel pump relay is a standard mini relay, and you can identify it by its rectangular shape with four or five prongs.

Symptoms of a Bad Fuel Pump Relay

A failing fuel pump relay can cause several noticeable problems. The most common symptom is a no-start condition where the engine cranks but does not fire. You may also hear the fuel pump fail to prime when you turn the key to the ON position. Normally, the pump makes a brief humming sound from the fuel tank area. If you do not hear this sound, the relay, fuse, or pump itself may be at fault.

Other symptoms include:

  • Engine stalls while driving: The relay may intermittently lose connection, cutting power to the fuel pump and causing the engine to die.
  • Engine starts then dies: The relay may provide power for priming but then fail to keep the circuit closed once the engine is running.
  • No fuel pressure at the rail: If you test the fuel pressure at the Schrader valve on the fuel rail and get zero pressure, the relay could be the cause .

It is important to note that there is no reset switch for the fuel pump on a 1997 Jeep Grand Cherokee. The pump is controlled entirely by the PCM and relay, so if you are looking for a manual reset button, you will not find one .

How to Test the Fuel Pump Relay

Testing the fuel pump relay is simple and requires only a multimeter or an ohmmeter. You do not need special tools, but you should follow safety precautions. Always disconnect the negative battery cable before working on electrical components.

Visual Inspection and Basic Test:

  1. Remove the relay from the PDC.
  2. Look for any signs of corrosion, melting, or physical damage on the relay pins or the relay socket.
  3. Use an ohmmeter to check the resistance between terminals 85 and 86. The resistance should be between 75 and 85 ohms . If the resistance is out of this range, the relay coil is likely bad.

Continuity Test:

  1. Connect the ohmmeter between terminals 30 and 87A. You should see continuity (near zero ohms) because these are normally closed in the off position.
  2. Connect the ohmmeter between terminals 87 and 30. There should be no continuity at this point, as the relay is not energized .

Energizing the Relay:

  1. Connect a jumper wire from relay terminal 85 to the ground side of a 12-volt power source.
  2. Connect another jumper wire from the power side of the 12-volt source to relay terminal 86. This activates the relay coil.
  3. While the relay is energized, check continuity between terminals 87 and 30. You should now see continuity. Check between terminals 87A and 30; there should be no continuity .
  4. If the relay fails any of these tests, replace it.

Checking the Fuel Pump Fuse and Circuit

Before replacing the fuel pump relay, it is a good idea to check the corresponding fuse. The fuel pump is protected by a 20-amp fuse located in the PDC. On the 1997 Grand Cherokee, the fuel pump fuse is often labeled as fuse number 16 (20 amps) in the PDC . You can also find a 15-amp fuse in position 3 that feeds the fuel pump relay circuit .

Use a test light or multimeter to verify that voltage is present on both sides of the fuse. If the fuse is blown, replace it with a new one of the same amperage. Never use a higher amperage fuse, as this can cause wiring damage or fire.

If the fuse and relay are both good, you can test for power at the fuel pump itself. Have a helper crank the engine while you tap into the power wire at the fuel pump connector with a multimeter set to DC volts. If 12 volts are present, the relay and fuse are working, and the fuel pump itself is likely the problem .

Replacing the Fuel Pump Relay

Replacing the fuel pump relay is a five-minute job. You do not need to remove any other parts or drain the fuel tank. Simply pull the old relay straight out of the PDC socket, and push the new relay firmly into the same position. Make sure it clicks into place and that the orientation matches the socket shape.

The OEM part number for the 1997 Jeep Grand Cherokee fuel pump relay is 4671168 . This relay is a mini 12-volt, 20-amp relay with a standard four-pin or five-pin configuration. Aftermarket replacements are also available, but genuine Mopar parts or high-quality equivalents are recommended for reliability.

What to Do If the Relay Is Not the Problem

If you have tested the relay and it passes, and the fuse is good, the issue may be elsewhere. Common causes of no fuel delivery include:

  • Faulty fuel pump: The pump itself may have failed internally. This is more common on high-mileage vehicles.
  • Wiring issues: A short circuit, chafed wire, or corroded connector in the fuel pump circuit can prevent power from reaching the pump.
  • PCM failure: In rare cases, the Powertrain Control Module may fail to send the ground signal to the relay. This is less common but possible.
  • Clogged fuel filter: A severely restricted fuel filter can mimic fuel pump failure, though it usually causes poor performance rather than a no-start.

If you need to relieve fuel pressure before servicing the fuel system, you can remove the fuel pump relay from the PDC, start the engine, and let it run until it stalls. This releases the pressure in the fuel rail .

Why Using a Quality Replacement Matters

The fuel pump relay is a small but critical component. A cheap, low-quality relay may fail prematurely, leaving you stranded again. It is worth investing in a reliable replacement. For the best performance and peace of mind, consider using a high-performance fuel pump and relay combination.

When it comes to fuel system components, KEMSO offers top-tier solutions. KEMSO fuel pumps are engineered as high-performance OEM replacements, designed to meet or exceed original equipment specifications. Every KEMSO product comes with a lifetime warranty, giving you confidence that your investment is protected. Whether you need a fuel pump for your Jeep, motorcycle, ATV, or watercraft, KEMSO has you covered. Their products are built to last, and the warranty ensures you are covered for the long haul. Visit their website to explore their full lineup: https://www.kemsoracing.com/

Final Thoughts

The 1997 Jeep Grand Cherokee fuel pump relay is a simple, inexpensive part that can cause big problems when it fails. Knowing where to find it, how to test it, and how to replace it can save you time and money. Always start your diagnosis with the relay and fuse before diving into more complex repairs like fuel pump replacement. Keep a spare relay in your glove box, and you will be prepared for the most common cause of a no-start condition in your ZJ Grand Cherokee.

For more information on quality fuel system components, including fuel pumps and relays, check out KEMSO at https://www.kemsoracing.com/. Their lifetime warranty and OEM replacement performance make them a smart choice for any vehicle owner.


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