1999 Lincoln Town Car Fuel Pump Relay Location: Your Definitive Guide

Locating the fuel pump relay in your 1999 Lincoln Town Car is crucial when diagnosing a no-start or fuel delivery issue. This vital relay resides in the Central Junction Box (CJB), also commonly known as the passenger compartment fuse box, specifically situated behind the panel on the right-hand end of the instrument panel dashboard. This guide provides the exact steps and necessary details to find and service this component safely and effectively.

Finding the Central Junction Box (CJB)

The CJB is the primary fuse and relay center inside the passenger cabin of your Town Car. To access it, follow these steps:

  1. Open the Passenger Door: Ensure the door is fully open to give you comfortable working space and adequate lighting.
  2. Locate the End Trim Panel: On the far right-hand side of the dashboard, closest to the passenger door opening, you will see a rectangular plastic trim panel running vertically. This panel runs roughly from the top of the dash down towards the floor carpet.
  3. Remove the Panel: Firmly grasp the panel at its top and bottom edges. Pull the panel straight out towards the passenger seat. It is held in place by several plastic retaining clips and should release with moderate, even pressure. Avoid using excessive force or prying tools near the dashboard material to prevent damage.
  4. Expose the CJB: Once the trim panel is removed, you will see the black or gray plastic Central Junction Box housing mounted vertically. This box has numerous fuses visible from the side and one or more plastic covers.

Identifying the Fuel Pump Relay Within the CJB

  1. Locate the Relay Section: The CJB holds both fuses and relays. Relays are typically larger, square or rectangular plastic components plugging into the box. Look for removable plastic covers on the CJB. These covers often protect the relays. Gently unclip and remove any cover obscuring the relays themselves.
  2. Refer to the Diagram: The easiest and most accurate way to identify the fuel pump relay slot is to look for the identification diagram printed directly on the CJB housing or on the underside of the cover you just removed.
    • Specific Slot Location: Look for the slot labeled "Fuel Pump," "FP," "F/P," or possibly "Relay 10 (R10)". Ford's designation for the relay slot can vary slightly, but the label "Fuel Pump" is the clearest indicator. The slots are clearly numbered.
    • Part Number Verification: The fuel pump relay for the 1999 Town Car is a standard Ford relay. Common part numbers include F57B-14B192-AA, RY-102, or equivalently numbered aftermarket relays like Standard Motor Products RY-102 or Bosch 0 332 019 150. Its appearance is a standard Ford/ISO micro relay:
      • Small black plastic cube, roughly 1 inch square.
      • Has four or five metal blade terminals protruding from the bottom.
      • Typically has the relevant Ford or manufacturer's part number printed on the top or side.
  3. Visually Confirm: Once you've identified the likely slot using the diagram, visually inspect the relay plugged into that slot. While it might have the part number, its position according to the CJB diagram is the primary identifying feature.

Why the Fuel Pump Relay is Important

The fuel pump relay acts as an electronically controlled switch for the high current required by the fuel pump. When you turn the ignition key to the "Run" position, the Powertrain Control Module (PCM) sends a brief signal to the relay coil, which activates it. This action closes the relay's internal high-current contacts, allowing battery voltage to flow directly from the fuse box (specifically, the fuse protecting the fuel pump circuit – often Fuse 12, 20A, also in the CJB) through the relay and down to the fuel pump located inside the fuel tank at the rear of the vehicle. Without this relay closing, the pump receives no power, causing a no-start condition. A failed relay is a common cause of intermittent or complete fuel pump failure.

Symptoms Indicating a Potential Fuel Pump Relay Problem

  • Engine Cranks but Won't Start: This is the most obvious symptom. The starter motor turns the engine over, but the engine fails to fire because no fuel is being delivered to the injectors by the pump.
  • Intermittent Starting Issues: The car might start fine sometimes and fail to start on other occasions, seemingly randomly. This could point to a relay with failing internal contacts.
  • Loss of Power While Driving: A relay that fails while the engine is running will cause the fuel pump to shut off instantly, leading to immediate engine stalling. It may or may not restart afterward.
  • No Fuel Pump Prime Sound: When you first turn the ignition key to "Run" (before cranking), you should hear a distinct humming or buzzing sound for a few seconds coming from the rear of the car (the fuel tank area). This is the fuel pump pressurizing the system. If you don't hear this noise during key-on, the pump isn't getting power, potentially due to a failed relay, fuse, or the pump itself.
  • No Power to Fuel Pump: Testing confirms no voltage reaches the electrical connector at the fuel pump when the ignition is in "Run."

Testing or Replacing the Fuel Pump Relay

  1. Safety First: Turn the ignition key to the "OFF" position and remove it. Ensure the vehicle is parked safely and securely.
  2. Locate and Identify Relay: Follow the steps above to locate and correctly identify the fuel pump relay slot in the CJB.
  3. Remove the Relay: Firmly grasp the relay body. Pull it straight out from its socket using an even, steady pulling force. Avoid twisting or rocking it excessively. Listen and feel for the retaining clips releasing.
  4. Swap with a Known Good Relay: This is often the simplest diagnostic test, especially if another relay in the CJB shares the exact same part number (common on Fords). Relays like the horn relay or A/C clutch relay are frequently identical. Locate an identical relay elsewhere in the CJB using the diagram (e.g., Horn Relay). Carefully pull that known good relay and plug it into the fuel pump relay socket. Turn the ignition to "RUN" and listen for the fuel pump prime. If you now hear it (and the car may start), your original fuel pump relay is faulty. If you still don't hear the pump, the problem lies elsewhere (blown fuse, wiring, pump itself, PCM command issue).
  5. Bench Testing: A multimeter can be used to test the relay out of the vehicle:
    • Resistance Check (Coil): Set the multimeter to measure Ohms (Ω). Touch the probes to the two terminals that correspond to the relay coil (usually terminals 85 and 86 on a standard ISO micro relay). You should get a resistance reading typically between 50-120 Ohms. A reading of "OL" (Open Line) or infinity means the coil is broken; a reading near 0 Ohms indicates a shorted coil.
    • Contact Check (Normally Open): Set the multimeter to measure continuity (beep mode). The relay should have normally open contacts between terminals 30 (power in) and 87 (power out to pump). Touch probes to 30 and 87. There should be no continuity. Then apply 12 volts to the coil terminals (85 and 86) – use fused jumper wires or a small 12V battery. The multimeter should now show continuity (beep) between 30 and 87. If it fails either test, the relay contacts are faulty.
  6. Replacement: If testing confirms the relay is defective, purchase an exact replacement (match the part number or appearance). Plug the new relay firmly into the correct slot, ensuring the terminals align. Push it straight in until it seats fully. Reinstall the CJB cover and the dashboard end trim panel.

Important Precautions and Considerations

  • Proper Identification is Key: Always double-check the CJB diagram and relay label against the descriptions here. Using the wrong relay slot can damage other systems.
  • Avoid Jumping Terminals: Never attempt to jump power directly across the relay socket terminals with a wire unless you are highly experienced and understand the circuit. This can bypass critical protections and potentially cause short circuits or fire.
  • Inspect for Corrosion: When the relay is removed, inspect its metal terminals and the corresponding terminals in the socket for any signs of corrosion, dirt, or damage. Clean them carefully with an electronics cleaner spray and a small brush if needed.
  • Fuse Check: Always check the associated fuel pump fuse (usually Fuse 12 in the CJB, often a 20A mini fuse). A blown fuse will prevent power even if the relay is good. Replace a blown fuse only with one of identical amperage.
  • It Might Not Be the Relay: While a common culprit, a no-start condition can stem from numerous sources: a completely failed fuel pump, a clogged fuel filter, a faulty fuel pump inertia switch (which cuts pump power in a collision, sometimes triggered by a bump – check its position and reset it), a faulty ignition switch, a crankshaft position sensor, wiring damage (especially common where the wiring harness passes through the trunk lid hinge area on Town Cars), or even a security system issue (like a failed PATS transponder chip in the key). The relay swap test is a vital first step in narrowing down the cause.
  • Safety Around Fuel: Remember that the fuel pump circuit powers the device supplying fuel. While working on this system carries minimal fire risk during simple relay testing/replacement (no fuel lines are opened near the CJB), always use caution and avoid sparks or open flames near the vehicle, especially near the fuel tank. Never smoke.

Conclusion

Diagnosing a suspected fuel pump issue on your 1999 Lincoln Town Car should always begin with checking the simplest and most accessible components. The fuel pump relay is located inside the Central Junction Box (CJB) mounted vertically behind the passenger-side end trim panel of the dashboard. By precisely identifying its slot using the provided diagram, testing it via the reliable swap method with an identical relay, and replacing it if necessary, you can often resolve frustrating starting problems quickly and inexpensively. Always remember to prioritize safety by turning off the ignition, work methodically using the CJB diagram, and consider checking the related fuel pump fuse as part of your initial inspection. Accurate identification and basic testing procedures empower you to get your Town Car back on the road.

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