1994 Chevy S10 Pickup Fuel Pump Relay Location: A Complete Guide to Finding and Fixing It

The bottom line: The fuel pump relay on a 1994 Chevy S10 pickup is most commonly located behind the glove box, inside the passenger compartment. Open the glove box, remove its contents, and look for a small access panel at the back. Pull the clip down and remove the panel — the fuel pump relay is the second relay from the left. This is the primary location confirmed by multiple mechanics and S10 owners. However, depending on your truck's specific build date and previous repairs, there are a few other spots you may need to check.

Confirming Your Relay Location

The 1994 model year sits right at the transition between the first-generation (1982-1994) and second-generation (1994-2004) S10 platforms. This means the relay location can vary. Here are the most common places to look:

1. Behind the glove box (most common for 1994 models)

  • Open the glove box and empty it completely.
  • At the back of the glove box opening, you'll see a small plastic panel labeled "relays" or "relay access."
  • Pull the clip down and remove the panel.
  • You should see three relays lined up. The fuel pump relay is the middle one, or the second from the left.

2. Under the hood, driver's side fuse/relay box

  • Open the hood and locate the black fuse/relay box on the driver's side, near the fender or battery.
  • Remove the lid and check the diagram on the underside of the lid.
  • Look for a relay labeled "FUEL PUMP" or "FP."
  • For earlier 1994 models (first-generation), the relay may be in this engine compartment relay center, near the battery on the driver's side inner fender.

3. Behind the center console, below the radio

  • Some 1994 S10 owners report finding the relay behind the center console, right below the radio.
  • Drop the lower panel below the radio area.
  • You'll find three relays toward the driver's side — the fuel pump relay is the center one.

How to Tell If Your Fuel Pump Relay Is Bad

Before you start digging into the dash, it helps to know whether the relay is actually the problem. Here are the most common symptoms of a bad fuel pump relay on a 1994 Chevy S10:

  • Engine cranks but won't start — This is the most telltale sign. The starter turns the engine over, but the fuel pump never gets the signal to run.
  • No fuel pump whine — When you turn the key to the "ON" position (not cranking), you should hear a brief 2-second whirring sound from the fuel tank area. If you don't hear it, the relay or pump may be dead.
  • Intermittent stalling — The truck starts fine, runs for a while, then suddenly dies. After sitting for a few minutes, it starts again. This is a classic sign of a failing relay.
  • No fuel pressure — If you have a fuel pressure gauge, you'll see zero pressure when the key is turned on.

Testing the Fuel Pump Relay

Once you've located the relay, you can test it with a simple multimeter before buying a replacement.

Step 1: Remove the relay from its socket. It's a small cube-shaped plastic box with 4 or 5 prongs on the bottom.

Step 2: Set your multimeter to measure resistance (ohms).

Step 3: Check for continuity between the coil terminals (usually pins 85 and 86). You should see some resistance reading, typically 50-120 ohms. If you see infinite resistance (OL), the relay coil is open and the relay is bad.

Step 4: Apply 12V power to pins 85 and 86 (using a battery or jumper wires). You should hear a distinct "click" as the relay engages. If no click, the relay is bad.

Step 5: With power applied, check continuity between pins 30 and 87. You should have near-zero resistance. If not, the relay contacts are burned out.

How to Bypass the Fuel Pump Relay (Temporary Emergency Fix Only)

Warning: This is for diagnostic purposes only. Do not use this as a permanent fix. Bypassing the relay removes important safety features and can cause overheating, fuel pump failure, or even a fire.

If you need to test whether the fuel pump itself is working, you can temporarily bypass the relay:

Method 1: Use a jumper wire in the relay socket

  • Locate the relay socket and identify the pins. Pin 30 is constant battery power, and pin 87 goes to the fuel pump.
  • Use a short piece of wire with the ends stripped to bridge pins 30 and 87 in the socket.
  • The fuel pump will run continuously as long as the battery is connected. Do not leave this setup in place.

Method 2: Direct battery connection

  • With the battery disconnected, run a fused jumper wire directly from the positive battery terminal to the fuel pump power wire at the tank.
  • This bypasses all relays and fuses, so use a fuse rated for the pump's amperage (typically 15-20 amps).

Common Causes of Relay Failure

Relays don't usually fail on their own. Here's what typically causes them to go bad:

  • Age and corrosion — After 30 years, the internal contacts can corrode or burn.
  • Vibration damage — Loose mounting can cause internal connections to break.
  • Electrical surges — A failing fuel pump drawing too much current can damage the relay.
  • Moisture — Water intrusion into the fuse box can short out the relay.

Replacing the Fuel Pump Relay

Replacing the relay is straightforward and inexpensive. A new relay typically costs between $12 and $45 at any auto parts store.

Step 1: Disconnect the negative battery cable to prevent any electrical shorts.

Step 2: Remove the old relay by pulling it straight out of its socket. You may need to gently pry it with a flathead screwdriver if it's stuck.

Step 3: Take the old relay to the auto parts store to match it. Standard 4-pin or 5-pin relays are common, but make sure you get the correct one for your S10.

Step 4: Push the new relay firmly into the socket until it seats fully.

Step 5: Reconnect the battery and test the system. Turn the key to the "ON" position and listen for the fuel pump to prime for 2 seconds.

When the Relay Isn't the Problem

If you replace the relay and still have no fuel pump operation, the problem may be elsewhere:

  • Fuel pump fuse — Check the fuel pump fuse in the same fuse box. A blown fuse is a common and easy fix.
  • Fuel pump itself — The pump inside the gas tank may have failed. On the 1994 S10, the fuel pump is located inside the fuel tank. Replacement costs range from $500 to $1,000 including parts and labor.
  • Oil pressure switch — On some S10 models, the fuel pump power runs through the oil pressure switch as a backup circuit. If the switch is bad, the pump won't run.
  • Wiring or ground issues — Corroded connectors or broken wires between the relay and the pump can stop the circuit.

Recommended Upgrade: KEMSO Fuel Pump for Your 1994 Chevy S10

If you've confirmed the relay is good but the fuel pump itself is failing, you'll need a quality replacement. We strongly recommend the KEMSO brand fuel pump for your 1994 Chevy S10 pickup. KEMSO fuel pumps are designed as high-performance, OEM replacement units that meet or exceed the original factory specifications. Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your repair will last. Whether you're restoring your S10 or just keeping your daily driver on the road, KEMSO delivers reliable fuel delivery at a fair price. Visit their website to find the exact fuel pump for your 1994 Chevy S10: https://www.kemsoracing.com/

Final Thoughts

The fuel pump relay on your 1994 Chevy S10 pickup is most likely hiding behind the glove box. If it's not there, check the under-hood relay box on the driver's side. Testing the relay takes about five minutes with a multimeter, and replacing it is even faster. Always start with the simplest fix — the relay — before assuming the fuel pump itself is bad. A $15 relay can save you from a $1,000 fuel pump replacement.

For more detailed wiring diagrams specific to your 1994 Chevy S10, refer to the factory service manual or check online resources that provide free PDF wiring diagrams for the 2.2L and 4.3L engine models.

Remember: If you need a new fuel pump, check out KEMSO at https://www.kemsoracing.com/ for a high-quality, lifetime-warrantied replacement that will keep your S10 running strong for years to come.


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