1999 Ford Windstar Fuel Pump Relay Location: A Complete DIY Guide

Here's precisely where to find the fuel pump relay in your 1999 Ford Windstar and what to do next: The fuel pump relay (often labeled as Relay #203, "PCM Relay," or "Fuel Pump Relay") is located inside the Central Junction Box (CJB) under the hood. Open the main engine compartment fuse box, typically found on the passenger side near the firewall/bulkhead. Locate the specific relay slot designated in the fuse box lid diagram – this diagram is your essential key. Replacing a faulty relay is a common and relatively simple solution when the fuel pump doesn't receive power.

Knowing the 1999 Ford Windstar fuel pump relay location is crucial for diagnosing and fixing common fuel delivery problems. The fuel pump relay acts as an electrically controlled switch commanded by the Powertrain Control Module (PCM). It provides the high current required to operate the fuel pump. When this relay fails, the pump doesn't run, preventing fuel from reaching the engine – a situation that obviously leaves the van stranded. Accessing it requires little more than locating the main fuse box under the hood and identifying the correct component based on the diagram.

Finding the 1999 Windstar Central Junction Box (CJB)

  1. Pop the Hood: Ensure the vehicle is parked on level ground with the engine off and the ignition key removed. Engage the parking brake. Release the hood latch inside the cabin, then go to the front of the van and lift the hood, securing it with the prop rod.
  2. Locate the Fuse Box: On the 1999 Ford Windstar, the Central Junction Box (CJB) is situated in the engine compartment. Look for a large, rectangular black plastic box.
    • Primary Location: It is almost always mounted on the passenger side of the engine bay.
    • Landmarks: Find it near the firewall (the solid metal wall separating the engine compartment from the cabin) and/or attached to the inner fender (the body panel directly behind the passenger-side front wheel). It's positioned away from extreme heat sources like the exhaust manifold but easily accessible once the hood is open.
  3. Open the CJB Lid: The CJB has a plastic cover protecting the fuses and relays inside. This cover usually snaps on. Find the latches or clips (often located on the front and back sides of the cover) and release them. Lift the cover straight up. Some force might be needed if the latches are stiff due to age or exposure. Set the cover aside carefully.

Identifying the Correct Fuel Pump Relay

Opening the CJB lid reveals an array of fuses (usually color-coded) and several similarly shaped black cubes – the relays. Here's how to pinpoint the right one:

  1. Consult the Diagram (MOST CRITICAL STEP): The inside of the CJB cover holds the definitive answer. Flip the cover over. You will find a detailed fuse and relay map molded or printed onto the plastic. This diagram identifies every fuse and relay slot numerically and functionally. Never skip this step. Diagrams can vary slightly depending on specific Windstar trim levels and options. Never rely solely on internet pictures for this specific detail – use the diagram on your van's cover.
  2. Look for "Relay #203", "Fuel Pump", "PCM Relay", or "FP Relay": Scan the diagram for the relay section. The relays are usually labeled with numbers. For the 1999 Windstar:
    • The slot you need is very commonly labeled "Relay 203". This relay often serves dual functions: powering the PCM and the fuel pump simultaneously. In some model variations or diagrams, it may simply be labeled "Fuel Pump Relay" or "FP Relay".
    • If "203" isn't listed or the labels differ, systematically look for any relay designation associated with "Fuel Pump", "PCM", or "FP".
  3. Identify the Physical Slot: Once you know the correct diagram designation (e.g., "Relay 203"), match that number to the actual slot inside the CJB. The slots are typically labeled clearly with embossed numbers (like "201", "202", "203", etc.) on the CJB itself, next to each relay position.
  4. Examine the Suspect Relay: Relays are usually standard ISO mini or micro relays (roughly 1-inch cubes). They plug into sockets with 4 or 5 terminal blades. The fuel pump relay will look identical in shape and size to many other relays in the CJB (e.g., horn relay, A/C relay). The diagram is the ONLY reliable way to distinguish it. Do not assume its position.

Why Finding the Relay is the First Step in Troubleshooting

When your 1999 Windstar cranks but won't start, a silent fuel pump is a prime suspect. Since the relay is the component that tells the pump to run, it's logically the easiest and cheapest part to check before condemning the pump itself, which requires dropping the fuel tank and is far more labor-intensive and expensive. Confirming the relay's location allows you to test it or quickly swap it with a known working relay (like the horn relay - only after confirming it's identical and verifying using the horn afterward!) for diagnosis.

Symptoms Pointing to a Potential Faulty Fuel Pump Relay

  • Cranks but Won't Start: The engine turns over normally but never catches and runs. This is the classic symptom.
  • No Fuel Pump Prime Sound: When you first turn the ignition key to the "ON" position (before cranking), you should hear a distinct humming or whirring sound from the rear (fuel tank area) for 2-3 seconds. This is the pump priming the system. Absence of this sound strongly suggests a power delivery issue (relay, fuse, wiring fault) or a dead pump. Always listen for this sound during diagnosis.
  • Intermittent Stalling / No Start: If the relay is failing intermittently, the engine might suddenly die while driving or fail to start only occasionally. The van might restart after cooling off.
  • Relay Audible Click Absence: If you have someone turn the key to "ON" while you have your ear near the CJB, a healthy relay will produce an audible "click" when energized. The absence of a click suggests the relay itself isn't receiving the signal to activate or is internally failed. (Note: A click doesn't guarantee the relay's internal contacts are good, but a lack of click is suspicious).

How to Remove and Inspect the Relay

  1. Battery Safety: Before handling any electrical components, disconnect the negative (-) battery cable. Use the correct size wrench. Place the cable end somewhere where it cannot accidentally touch the battery terminal. This prevents sparks and short circuits.
  2. Grip and Pull: The relay plugs snugly into its socket. Grasp it firmly along its sides. Pull straight up with steady pressure. Avoid twisting or rocking it excessively, as this can damage the socket terminals. If stuck, gently wiggle slightly while pulling upwards.
  3. Visual Inspection: Examine the relay's terminal blades and the socket contacts for any obvious signs of:
    • Corrosion: A white/green powdery substance on the metal terminals.
    • Melting/Heat Damage: Warped plastic relay housing, burnt odor, discolored or darkened contacts.
    • Loose Contacts: Wiggling terminals inside the relay base. Severe corrosion, melting, or bent/broken terminals indicate a problem needing attention beyond just a relay swap.

The Role of the Fuse: Don't Forget It!

While the relay switches the high current, a dedicated fuse protects the fuel pump circuit.

  1. Consult the Diagram (Again!): Go back to the diagram on the CJB lid. Find the fuse specifically designated for the Fuel Pump circuit. This is often a high-amperage fuse (15A, 20A, or 30A).
  2. Physical Identification: Fuses are smaller than relays and have a transparent top so you can see the fuse element. The rating (e.g., 15, 20, 30) is usually embossed on top. Each fuse slot in the CJB is numbered. Match the diagram designation to the slot number.
  3. Testing the Fuse: Visually inspect the small metal wire inside the clear plastic body. If it's visibly broken or the center appears melted/burnt, the fuse is blown. Use a multimeter set to continuity mode or ohms mode to verify – a good fuse shows near zero resistance/continuity beep; a blown fuse shows infinite resistance/open circuit. ALWAYS replace a blown fuse with one of the EXACT same amperage rating.
  4. Why Fuse and Relay Together? It's very common to check both simultaneously. A blown fuse might explain why the relay clicks but the pump doesn't run. A blown fuse could also be caused by a short circuit downstream (like a failing pump motor or damaged wiring), so if a new fuse blows immediately upon replacement, you have a more serious problem.

Testing the Fuel Pump Relay (Beyond the Click Test)

While the simple swap test with a similar relay is often effective, more thorough verification is possible:

  1. Basic Bench Shake Test: An internally broken relay might rattle if shaken slightly – indicating failure.
  2. Bench Testing with a Multimeter:
    • Identify Terminals: Most standard automotive relays have markings near the blade terminals:
      • 85 and 86: Low current coil terminals (the electromagnet).
      • 30: Common contact (input power from battery).
      • 87: Normally Open (NO) contact (output to the device, e.g., fuel pump).
      • 87a: Normally Closed (NC) contact (rarely used in fuel pump circuits; usually unmarked on a 4-pin relay).
    • Coil Continuity Test: Set multimeter to Resistance (Ohms) mode. Touch probes to terminals 85 and 86. You should read a moderate resistance value (typically between 50-120 ohms) indicating the coil is intact. Infinite resistance = Open Coil = Bad Relay.
    • Contact Test (De-energized):
      • 4-Pin Relay (common): Touch probes between 30 and 87. Should show infinite resistance (open circuit).
      • 5-Pin Relay: Touch probes between 30 and 87 (should be open), and between 30 and 87a (should show low resistance/short circuit).
    • Contact Test (Energized): Apply 12 volts (a small battery or dedicated power supply) across terminals 85 (+) and 86 (-). You should hear/feel a distinct click.
      • 4-Pin Relay: Probes on 30 and 87 should now show very low resistance (near zero ohms).
      • 5-Pin Relay: Probes on 30 and 87 should show low resistance; probes on 30 and 87a should now show infinite resistance.
  3. In-Circuit Voltage Testing (Advanced): This requires careful probing with the relay plugged in and power restored.
    • Terminal 30: Should have constant battery voltage (12V+) measured with ignition OFF and ON.
    • Terminal 85: Should show ground (-) when ignition is ON (measured relative to battery ground). This signal comes from the PCM.
    • Terminal 86: PCM usually provides power on this terminal to complete the coil circuit. Should show 12V+ with ignition ON.
    • Terminal 87: Should show 12V+ only when the ignition is ON and the relay clicks/closes (supplying power to the fuel pump). If relay clicks but 87 shows no voltage, internal contacts are bad. Exercise extreme caution probing energized circuits; avoid shorting probes.

Replacing the 1999 Ford Windstar Fuel Pump Relay

  1. Obtain the Correct Replacement: Use the relay removed from the van as your guide. Confirm it matches physically (pin count, size). Standard ISO relays are common, but purchasing the correct amperage rating specified by Ford is safest. Options:
    • Ford Dealership Parts Counter (Guaranteed OE match)
    • Reputable Auto Parts Store (NAPA, AutoZone, O'Reilly, etc.). Provide them your VIN.
    • Ensure it's labeled for use in fuel pump or PCM circuits – it must handle the required current.
  2. Installation: Ensure the ignition is OFF and the battery is disconnected (Negative cable). Orient the new relay so its blade terminals align with the slots in the socket. Push straight down firmly and evenly until it's fully seated. You should feel/hear it click into place. Avoid forcing it. Double-check it's secure.
  3. Reconnect Battery: Reattach the negative battery cable securely.
  4. Functional Test: Turn the ignition key to the "ON" position. Listen carefully: You should hear the fuel pump prime for 2-3 seconds. Attempt to start the engine. If it starts and runs, the relay replacement was likely successful.
  5. Reinstall CJB Cover: Snap the protective cover securely back onto the Central Junction Box.

When Replacing the Relay Doesn't Solve the Problem

If a new relay and verified good fuse don't restore fuel pump operation:

  1. Check Fuel Inertia Switch: While more likely to cause a problem after an impact, this safety cutoff switch (usually located on the passenger-side footwell near the kick panel or behind the glovebox) can trip and cut fuel pump power. Locate it and press the reset button. Refer to your owner's manual for its specific location and instructions.
  2. Wiring Harness Inspection: Look for damaged, frayed, or corroded wiring in the engine compartment (near the CJB), under the van leading to the fuel tank, and at the fuel pump connector itself. Pay attention to areas near heat sources, moving parts, or previous repair points.
  3. Fuel Pump Ground: A poor ground connection can prevent the pump from operating even if it has power. Locate the ground wire connection for the pump (often near the tank or at a body ground point) and clean it thoroughly.
  4. Direct Power Test: Applying 12V directly to the fuel pump wiring harness connector (at the tank access point) is a definitive pump test. This bypasses the relay, fuse, and wiring. This test carries risk of sparks near fuel vapors and should only be done following strict safety protocols (disconnect battery, ensure good ventilation, quick connection/disconnection away from tank). If the pump doesn't run when directly powered (with known good wires and connections), the pump itself is almost certainly failed.
  5. PCM Signal: It's less common, but a failure within the PCM preventing it from grounding the relay control circuit (Terminal 85) would prevent the relay from activating. Diagnosing this often requires advanced scan tools or professional help. Check basic PCM power and grounds first.

Conclusion: Knowledge Saves Time and Money

Successfully locating the 1999 Ford Windstar fuel pump relay location (Central Junction Box, under hood, passenger side, use the lid diagram!) empowers you to tackle one of the most common causes of a "cranks but won't start" situation. Remember the critical steps: listen for the prime sound, check fuse and relay using the diagram, swap a known good relay safely, test before condemning the pump. This relatively simple component check can often save a significant amount of diagnostic time and expensive repair costs versus immediately replacing the fuel pump. Always prioritize safety by disconnecting the battery before handling relays and fuses. If the problem persists beyond the relay and fuse, systematic wiring checks or pump testing will be necessary. With this guide, you have the essential starting point.

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