LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mercury >> 1993 >> Villager LS >> Repair and Diagnosis >> Body & Frame >> Power Windows >> System Tests >> Power Window System Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Power Window System Test

SYMPTOM INDEX

Symptom Perform Test Procedure Step No.
Power Windows And Power Quarfter Glasses Are Completely Inoperative  1
Main Power Window Switch Does Not Work  13
One-Touch Down Feature Does Not Work  15
Left Front Power Window Does Not Work  15
Right Front Power Window Does Not Work  15
Right Front Power Window Does Not Work Using Passenger Switch  24
Both Rear Power Quarter Glasses Do Not Work  29
Left Rear Power Quarter Glass Does Not Work  31
Right Rear Quarter Glass Does Not Work  34
  1. Check the RLY COIL fuse (10 amp) located in the interior fuse panel. Check the POWER WINDOW fuse (30 amp) located in the left hand engine compartment fuse panel. Are the fuses okay? If yes, then go to step  5 . If not, then go to next step.
  2. Turn the ignition switch to OFF. Replace the RLY COIL fuse (10 amp) and/or the POWER WINDOW fuse (30 amp). Turn the ignition switch to ON. Inspect the fuses. Do the fuses fail again? If the RLY COIL fuse fails go to next step. If the POWER WINDOW fuse fails, go to step  4 . If neither fuse fails, go to step  5 .
  3. Remove the RLY COIL fuse (10 amp). Disconnect the power window relay located behind the interior fuse panel. Disconnect the power window amplifier connector located behind the left door panel. Measure the resistance of the Blue wire between the right terminal of the RLY COIL fuse (10 amp) and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms. If yes, then repair the Blue wire. If not, then replace the RLY COIL fuse (10 amp) and go to step  5 .
  4. Remove the POWER WINDOW fuse (30 amp). Disconnect the circuit breaker connector located behind the interior fuse panel. Measure the resistance of the White/Blue wire between the terminal nearest the battery of the POWER WINDOW fuse (30 amp) and ground. See WIRING DIAGRAMS  . Is the resistance greater than 10,000 ohms. If yes, then replace the POWER WINDOW fuse (30 amp), reconnect circuit breaker connector and go to next step. If resistance is less than 10,000 ohms repair White/Blue wire. Retest system for normal operation.
  5. Disconnect the power window relay located behind the interior fuse panel. Turn ignition switch to ON. Measure the voltage on the Blue wire at the power window relay connector. See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to next step. If not, then service the Blue wire between the interior fuse panel and the power window relay.
  6. Turn the ignition switch to OFF. Disconnect the power window relay. Measure the voltage on the Light Green wire at the power window relay connector. See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to step  9 . If not, then go to next step.
  7. Disconnect the circuit breaker connector. Measure the voltage on the White/Blue wire at the circuit breaker connector. See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to next step. If not, then service the White/Blue wire between the interior fuse panel and the right hand circuit breaker.
  8. Remove the power window relay. Disconnect the circuit breaker connector. Measure the resistance of the Light Green wire between the circuit breaker connector and the power window relay connector. See WIRING DIAGRAMS  . Measure the resistance of the Light Green wire between the circuit breaker connector and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms between the circuit breaker connector and the power window relay connector, and greater than 10,000 ohms between the circuit breaker connector and ground? If yes, then replace the circuit breaker. If not, then service the Light Green wire.
  9. Remove the power window relay. Measure the resistance of the Black wire between the power window relay connector and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then go to step  12 . If not, then go to next step.
  10. Remove the instrument cluster connector. Disconnect the center black diode strip from the diode junction box connector located behind the instrument cluster. Measure the resistance of the Black wire between the power window relay connector and Pin 13 of the diode junction box connector. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then go to next step. If not, then service the Black wire.
  11. Disconnect the center black diode strip from the diode junction box connector. Measure the resistance of the Black/Red wire between Pin 15 of the diode junction box connector and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then replace the diode strip. If not, then service the Black/Red wire.
  12. Test power window relay. See RELAY  under COMPONENT TESTS. If the relay operates as specified, reinstall relay into system and go to next step. If not, then replace relay and retest system for normal operation.
  13. Disconnect the main power window switch connector located on the left hand door panel. Disconnect the rear power quarter glass switch connector located on the overhead console. Disconnect the passenger power window switch connector located on the right door panel. Disconnect the power window amplifier connector located behind the left door panel. Turn ignition switch to ON. Measure the voltage on the Light Green/Yellow wire at the main power window switch connector. See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to next step. If not, then repair the Light Green/Yellow wire.
  14. Turn the ignition switch to OFF. Disconnect the main power window switch connector. Measure the resistance of the Black wire between the main power window switch connector and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then go to next step. If not, then repair the black wire.
  15. Test power window main switch. See POWER WINDOW SWITCH  under COMPONENT TESTS. If the switch operates as specified, go to next step. If the switch does not operate as specified, replace switch. See POWER WINDOW SWITCH  under REMOVAL & INSTALLATION.
    16. NOTE: Power window amplifier is also know as a power window module.
  16. With the ignition switch in OFF, disconnect the power window amplifier connector. Turn the ignition switch to ON. Measure the voltage on the Blue wire at the power window amplifier connector. Measure the voltage on the Orange/Black wire at the power window amplifier connector. See WIRING DIAGRAMS  . Is each voltage greater than 10 volts? If yes, then go to next step. If not, the service the faulty circuit.
  17. Turn the ignition switch to OFF. Disconnect the power window amplifier connector. Measure the resistance of the Black wire between the power window amplifier connector and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then go to next step. If not, then repair the Black wire.
  18. Test the power window amplifier. See POWER WINDOW AMPLIFIER  under COMPONENT TESTS. If the power window amplifier is okay, go to step  22 . If not, then go to next step.
  19. Disconnect the main power window switch connector. Disconnect the power window amplifier connector located behind the left door panel. Measure the resistance of the following wires between the main power window switch connector and the power window amplifier connector:
    • Blue/Red Wire
    • Blue/White Wire
    • Blue Wire
    See WIRING DIAGRAMS  . Resistance at all terminals should be less than 5 ohms. If the resistances are as specified, go to next step. If the resistances are not as specified, repair faulty circuit.
  20. Measure the resistance of the following wires between the main power window switch connector and ground:
    • Blue/Red Wire
    • Blue/White Wire
    • Blue Wire
    See WIRING DIAGRAMS  . Resistance at all terminals should be greater than 10,000 ohms. If resistances are as specified, go to next step. If the resistances are not as specified, repair faulty circuit.
  21. Disconnect the left hand front power window motor assembly connector located behind the left door panel. Measure the resistance of the Blue/Red wire and the Pink wire between the power window amplifier connector and the left front power window motor assembly connector. Measure the resistance of the Blue/Red wire and the Pink wire between the power window amplifier connector and ground. See WIRING DIAGRAMS  . Are the resistances less than 5 ohms between the power window amplifier connector and the left front power window motor assembly connector, and greater than 10,000 ohms between the power window amplifier connector and ground? If yes, then replace the power window amplifier. See POWER WINDOW AMPLIFIER  under REMOVAL & INSTALLATION. If not, then repair the faulty circuit.
  22. Test left front power window motor. See MOTOR  under COMPONENT TESTS. If the power window motor operates as specified, go to next step. If power window does not operate as specified, replace motor. See MOTOR  under REMOVAL & INSTALLATION.
  23. Check ignition switch in OFF position. Disconnect the main power window switch connector. Disconnect the passenger power window switch connector located behind the right door panel. Measure the resistance of the Orange/Blue wire and the Light Green/Black wire between the main power window switch connector and the passenger power window switch connector. Measure the resistance of the Orange/Blue wire and the Light Green/Black wire between the main power window switch connector and ground. See WIRING DIAGRAMS  . Are the resistances less than 5 ohms between the main power window switch connector and the passenger power window switch connector, and greater than 10,000 ohms between the main power window switch connector and ground? If yes, then go to next step. If not, then repair faulty circuit.
  24. Turn the ignition switch to ON. Measure the voltage on the Orange/Black wire at the passenger power window switch connector. See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to next step. If not, then repair the orange/Black wire between the power window relay and the passenger power window switch.
  25. Reconnect the main power window switch. Turn the P/W LOCK switch off, on the main power window switch. Measure the resistance of the Orange/Blue wire and the Light Green/Black wire between the passenger power window switch connector and ground. See WIRING DIAGRAMS  . Are the resistances less than 5 ohms? If yes, then go to next step. If not, then replace the power window main switch. See POWER WINDOW SWITCH  under REMOVAL & INSTALLATION.
  26. Reconnect the passenger power window switch. Disconnect the right front power window motor assembly connector located behind the right door panel. Turn the ignition switch to ON. Check power window switch. See POWER WINDOW SWITCH  under COMPONENT TESTS. If the switch voltages are as specified, go to step  28 . If switch voltages are not as specified, go to next step.
  27. Turn the ignition switch to OFF. Disconnect the passenger power window switch connector. Disconnect the right front power window motor assembly connector located behind the right door panel. Measure the resistance of the Blue/Yellow wire and the Blue/Orange wire between the passenger power window switch connector and the right front power window motor assembly connector. Measure the resistance of the Blue/Yellow wire and the Blue/Orange wire between the passenger power window switch connector and ground. See WIRING DIAGRAMS  . Are the resistances less than 5 ohms between the passenger power window switch connector and the right hand front power window motor assembly connector, and greater than 10,000 ohms between the passenger power window switch connector and ground? If yes, then replace the passenger power window switch. See POWER WINDOW SWITCH  under REMOVAL & INSTALLATION. If not, then repair the faulty circuit.
  28. Test right front power window motor. See MOTOR  under COMPONENT TESTS. If the power window motor operates as specified, go to next step. If power window does not operate as specified, replace motor. See MOTOR  under REMOVAL & INSTALLATION.
  29. Turn the ignition switch to OFF. Disconnect the rear power quarter glass switch connector located on the overhead console. Turn the ignition switch to ON. Measure the voltage on the Orange/Black wire at the rear power quarter glass switch connector. See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to next step. If not, then service the Orange/Black wire between the power window relay and the rear power quarter glass switch.
  30. Measure the resistance of the Black wire between the rear power quarter glass switch connector and ground. See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then go to next step. If not, then repair the black wire.
  31. Test the left rear quarter glass motor. See MOTOR  under COMPONENT TESTS. If the power window motor operates as specified, go to next step. If power window does not operate as specified, replace motor. See MOTOR  under REMOVAL & INSTALLATION.
  32. Reconnect the rear power quarter glass window switch. Disconnect the left rear power quarter glass motor assembly connector. Turn the ignition switch to ON. Measure the voltage on the following wires at the left rear power quarter glass motor assembly connector. With the switch in OPEN, voltage should be greater than 10 volts at the Red/Yellow wire. With Switch in CLOSE, voltage should be greater than 10 volts at the Red/Black wire. See WIRING DIAGRAMS  . If the voltages are as specified, go to step  34 . If the voltages are not as specified, go to next step.
  33. Disconnect the rear power quarter glass switch connector. Disconnect the left rear power quarter glass motor assembly connector located behind the left quarter trim access panel. Measure the resistance of the Red/Yellow wire and the Red/Black wire between the rear power quarter glass switch connector and the left rear power quarter glass motor assembly connector. Measure the resistance of the Red/Yellow wire and the Red/Black wire between the rear power quarter glass switch connector and ground. Are the resistances less than 5 ohms between the rear power quarter glass switch connector and the left hand rear power quarter glass motor assembly connector, and greater than 10,000 ohms between the rear power quarter glass switch connector and ground? If yes, then replace the rear power quarter glass switch. See POWER WINDOW SWITCH  under REMOVAL & INSTALLATION. If not, then repair the faulty circuit.
  34. Test the left rear quarter glass motor. See MOTOR  under COMPONENT TESTS. If the power window motor operates as specified, go to next step. If power window does not operate as specified, replace motor. See MOTOR  under REMOVAL & INSTALLATION.
  35. Disconnect the rear power quarter glass switch connector. Disconnect the right rear power quarter glass motor assembly connector. Measure the resistance of the Red wire and the Orange/Blue wire between the rear power quarter glass switch connector and the right rear power quarter glass motor assembly connector. Measure the resistance of the Red wire and the Orange/Blue wire between the rear power quarter glass switch connector and ground. Are the resistances less than 5 ohms between the rear power quarter glass switch connector and the right hand rear power quarter glass motor assembly connector, and greater than 10,000 ohms between the rear power quarter glass switch connector and ground? If yes, then replace the rear power quarter glass switch. See POWER WINDOW SWITCH  under REMOVAL & INSTALLATION. If not, then repair the faulty circuit.
scientia non olet · About LEMON Manuals