LEMON Manuals: Even more car manuals for everyone
Home >> Mercury >> 1993 >> Villager LS >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panels - Electronic >> System Tests >> Test M: Brake Warning System

Test M: Brake Warning System

NOTE: Do NOT start this test unless directed by a symptom diagnosis in BRAKE WARNING SYSTEM  under TROUBLE SHOOTING.
  1. Check the 10A METER fuse located in the interior fuse panel. Is the fuse OK? If yes, go to step  4 . If no, go to next step.
  2. Turn ignition key to OFF position. Replace the 10A METER fuse. Turn ignition on. Inspect the fuse. Does the fuse fail again? If yes, go to next step. If no, go to step  4 .
  3. Turn off ignition. Remove the 10A METER fuse. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Disconnect all the instrument cluster connectors. Measure the resistance of the Gray/Blue wire between the right terminal of the 10A METER fuse and ground. Is the resistance greater than 10,000 ohms? If yes, replace the 10A METER fuse. Go to next step. If no, service the Gray/Blue wire between the interior fuse panel and the instrument cluster.
  4. Turn ignition off. Remove the instrument cluster. Disconnect the black 12-pin analog instrument cluster connector or the 20-pin electronic instrument cluster connector. Turn on ignition. Measure the voltage on Pin 1T (Gray/Blue) of the 20-pin electronic instrument cluster connector. See CONNECTOR IDENTIFICATION  . Is the voltage greater than 10 volts? If yes, go to next step. If no, service the Gray/Blue wire between the interior fuse panel and the instrument cluster.
  5. Turn ignition off. Remove the instrument cluster. Remove the brake warning lamp bulb on the instrument cluster. Measure the resistance between the terminals of the brake warning lamp bulb. Is the resistance about 15 ohms? If yes, go to  6 . If no, replace the brake warning lamp bulb.
  6. Turn ignition off. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Disconnect the 20-pin instrument cluster connector. Connect a test lamp between Gray/Blue wire and Yellow/Purple on the 20-pin instrument cluster connector. See CONNECTOR IDENTIFICATION  . Turn ignition on. Does the test lamp illuminate? If yes, go to next step. If no, replace the instrument cluster.
  7. Turn off ignition. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Disconnect the 20-pin electronic instrument cluster connector. Disconnect the low brake fluid level indicator switch connector located under the brake fluid reservoir. Remove the bulb check relay from the engine compartment relay block. See Figure . Disconnect the top black diode strip at the diode junction box located behind the instrument cluster.See Figure . Measure the resistance of the Yellow/Purple wire between the 20-pin electronic instrument cluster connector and ground. Is the resistance greater than 10,000 ohms? If yes, go to next step. If no, service the Yellow/Purple wire.
  8. Turn ignition off. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Disconnect the 20-pin electronic instrument cluster connector. Remove the bulb check relay from the engine compartment relay block. See Figure . Measure the resistance of the Yellow/Purple wire between the bulb check relay connector and the 20-pin electronic instrument cluster connector. Is the resistance less than 5 ohms? If yes, go to next step. If no, service the Yellow/Purple wire.
  9. Check the 10A RLY COIL fuse located in the interior fuse panel. Is the fuse OK? If yes, go to step  12 . If no, go to next step.
  10. Turn ignition off. Replace the 10A RLY COIL fuse. Turn ignition on. Inspect the fuse. Does the fuse fail again? If yes, go to next step. If no, go to step  12 .
  11. l Key OFF. l Remove the 10A RLY COIL fuse. l Remove the bulb check relay. l Measure the resistance of the "BL" wire between the right terminal of the 10A RLY COIL fuse and ground. l Is the resistance less than 5 ohms? Yes service the "BL" wire between the interior fuse panel and the bulb check relay. No REPLACE the 10A RLY COIL fuse. GO to BWL13.
  12. Turn off ignition. Remove the bulb check relay from the engine compartment relay block. See Figure . Measure the voltage on the Blue wire at the bulb check relay connector. Is the voltage greater than 10 volts? If yes, go to next step. If no, service the Blue wire between the interior fuse panel and the bulb check relay.
  13. Turn off ignition. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Remove the bulb check relay. Disconnect the top black diode strip at the diode junction box located behind the instrument cluster. See Figure . Measure the resistance of the Blue/Yellow wire between the bulb check relay connector and terminal 6 of the diode junction box connector. See Figure . Is the resistance less than 5 ohms? If yes, go to next step. If no, service the Blue/Yellow wire.
  14. Turn off ignition. Remove the bulb check relay from the engine compartment relay block. See Figure . Measure the resistance of the Black wire between the bulb check relay connector and ground. Is the resistance less than 5 ohms? If yes, go to next step. If no, service the Black wire.
  15. Turn ignition off. Remove the bulb check relay. Apply 12 volts to the Blue wire terminal at the bulb check relay. Measure resistance between the Yellow/Purple wire terminal and the Black wire terminal on the bulb check relay at the specified conditions. See BULB CHECK RELAY TEST  . Are the resistances OK? If yes, go to next step. If no, replace the bulb check relay.
    BULB CHECK RELAY TEST

    Bulb Check Relay Blue/Yellow Wire Terminal Resistance (Ohms)
    Grounded Less Than 5 Ohms
    Open Greater Than 10,000 Ohms
  16. Turn off ignition. Disconnect the low brake fluid level indicator switch connector located under the brake fluid reservoir. Gently remove the screen inside the brake fluid reservoir. Depress the brake fluid level float with a clean screwdriver. Measure the resistance between the terminals of the low brake fluid level indicator switch. Is the resistance less than 5 ohms with the brake fluid level float depressed, and greater than 10,000 ohms with brake fluid level float released? If yes, go to next step. If no, replace the low brake fluid level indicator switch.
  17. Turn off ignition. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Disconnect the 20-pin electronic instrument cluster connector. Disconnect the low brake fluid level indicator switch connector. Measure the resistance of the Yellow/Purple wire between the 20-pin electronic instrument cluster connector and the low brake fluid level indicator switch connector. See CONNECTOR IDENTIFICATION  . Is the resistance less than 5 ohms? If yes, go to next step. If no, service the Yellow/Purple wire.
  18. Turn off ignition. Disconnect the low brake fluid level indicator switch connector. Measure the resistance of the Black wire between the low brake fluid level indicator switch connector and ground. Is the resistance less than 5 ohms? If yes, go to next step. If no, service the Black wire.
  19. Turn off ignition. Disconnect the parking brake switch connector located on the parking brake pedal. Set the parking brake. Measure the resistance between the terminal on the parking brake switch and ground. Is the resistance less than 5 ohms with the parking brake set, and greater than 10,000 ohms with parking brake released? If yes, go to next step. If no, replace the parking brake switch.
  20. Turn off ignition. Remove the instrument cluster. See ELECTRONIC INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Disconnect the 20-pin electronic instrument cluster. Disconnect the top black diode strip at the diode junction box located behind the instrument cluster. See Figure . Measure the resistance of the Yellow/Purple wire between the 20-pin electronic instrument cluster connector and Pin 10 of the diode junction box connector. See Figure . Is the resistance less than 5 ohms? If yes, go to next step. If no, service the Yellow/Purple wire.
  21. l Key OFF. l Remove the instrument cluster. l Disconnect the top black diode strip at the diode junction box. l Disconnect the parking brake switch connector. Measure the resistance of the "GN/BK" wire between Pin 9 of the diode junction box connector and the parking brake switch connector. l Is the resistance less than 5 ohms? Yes REPLACE the top black diode strip on the diode junction box. No service the "GN/BK" wire.
scientia non olet · About LEMON Manuals