LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lincoln >> 1998 >> Navigator 4WD >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> System Tests >> Speed Control Inoperative
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Speed Control Inoperative

  1. Check Actuator Cable

    Remove snow shield from throttle linkage. Ensure actuator cable is properly connected to throttle body. Correct as necessary and test operation.

  2. Check Servo Power Circuit

    Unplug harness connector from servo located near master cylinder. Turn ignition on. Test for battery voltage between servo harness connector pins No. 7 and 10. See Figure . If battery voltage exists, go to step 4). If battery voltage does not exist, check fuse No. 5. Replace fuse if necessary If fuse is okay, go to next step.

  3. Check Servo Ground Circuit

    Turn ignition off. Measure resistance between harness connector pin No. 10 and ground. If resistance is less than 5 ohms, repair Light Blue/Pink wire. If resistance is not less than 5 ohms, repair Black wire to ground.

  4. Check Stoplight Switch

    With brake pedal released, test for voltage between servo harness connector pins No. 4 and 10. If voltage is zero, stoplight switch is okay. Go to next step. If battery voltage exists, replace stoplight switch (switch stuck on).

  5. Check Brake/Clutch Circuit

    Turn ignition off. Measure resistance between servo harness connector pins No. 4 and 10. If resistance is less than 20 ohms, go to next step. If resistance is greater than 20 ohms, check stoplight bulbs (including high mounted stoplight). Replace bulb(s) if necessary. If bulbs are okay, repair stoplight circuit.

  6. Check Deactivator Circuit

    With ignition off and brake pedal released, measure voltage between servo harness connector pins No. 9 and 10. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 10).

  7. Check Deactivator Switch

    Unplug connector from deactivator switch located on or near master cylinder. Measure resistance between switch terminals with brake pedal released. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, replace switch, then repeat step 5).

  8. Check Power To Deactivator Switch

    Test for battery voltage at pin No. 1 (Light Green/Red wire) at deactivator switch connector. If battery voltage exists, repair short in Black/Yellow wire. If battery voltage does not exist, repair open Light Green/Red wire from fuse panel. See WIRING DIAGRAMS.

  9. Check For Stuck ON Switch

    With no steering wheel switches pressed, measure voltage between servo harness connector pins No. 5 and 10. If voltage is less than 10 volts, go to next step. If voltage is greater than 10 volts, replace speed control command (ON/OFF) switch.

  10. Check Command Switch Operation

    With speed control ON switch depressed, measure voltage between servo harness connector pins No. 5 and 10. If voltage is less than 10 volts, go to next step. If voltage is greater than 10 volts, go to step 14).

  11. Check For Open Dark Green/Orange Wire

    Remove driver side air bag. See appropriate AIR BAG RESTRAINT SYSTEM article. Disconnect air bag sliding contact harness connector. Measure resistance of Dark Green/Orange wire between servo harness connector pin No. 6 and air bag sliding contact harness connector. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open in Dark Green/Orange wire. Retest system.

  12. Check Air Bag Sliding Contact For Open

    Remove driver side air bag. See appropriate AIR BAG RESTRAINT SYSTEM article. Disconnect air bag sliding contact harness connector. Measure resistance of Light blue/Black wire between air bag sliding contact harness connector and top of air bag sliding harness contact surface. If resistance is less than one ohm, go to next step. If resistance is greater than one ohm, replace air bag sliding contact. Retest system.

  13. Check ON Circuit

    With speed control ON switch depressed measure voltage between servo connector pins No. 5 (Light Blue/Black wire) and No. 10 (Black wire). If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, replace speed control command (ON/OFF) switch. Retest system.

  14. Check SET/ACCEL Switch

    With SET-ACCEL switch pressed, measure resistance between servo harness connector pins No. 5 (Light Blue/Black wire) and No. 6 (Dark Green/Orange wire). If resistance is 640-720 ohms, SET-ACCEL switch is okay. Go to next step. If resistance is not 640-720 ohms, replace SET-ACCEL switch.

  15. Check VSS Circuit

    Disconnect Vehicle Speed Sensor (VSS). Measure resistance of Gray/Black wire between servo harness connector terminal No. 3 and VSS harness connector. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open Gray/Black wire.

  16. Check For Broken Actuator Cable

    Disengage throttle actuator cable from servo. Inspect for broken cable by pulling end of cable and observing throttle movement. Replace cable if broken or binding. If cable is okay, replace servo.
scientia non olet · About LEMON Manuals