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Power Door Lock System Test

  1. Check Door Lock Fuse

    Access interior fuse panel. Is Power Door Lock Fuse (30 amp) ok? If yes then go to step  4 . If fuse is not OK, go to next step.
  2. Check System

    Replace power door lock fuse (30 amp). Turn ignition switch to ON position. Does fuse blow again? If yes, then go to next step. If not, then go to step  4 .
  3. Check For Short To Ground

    Turn ignition switch to OFF position. Disconnect White/Green wire from power door lock fuse. See WIRING DIAGRAMS  . Measure resistance of on end of White/Green wire to ground. Is the resistance less than 5 ohms? If yes, then repair White/Green wire between door lock fuse and power door lock relay. See Fig 1 . See WIRING DIAGRAMS  . If resistance is more than 5 ohms, replace power door lock relay.
  4. Check Power Supply To Relay

    Access power door lock relay. Turn ignition switch to ON position. Measure voltage at White/Green wire at power door lock relay connector. See Fig 1 . See WIRING DIAGRAMS  . Is the voltage greater than 10 volts? If yes, then go to next step. If not, then repair White/Green wire between power door lock relay and fuse (30 amp).
  5. Check Relay Ground

    Turn ignition switch to OFF position. Measure resistance of Black wire between power door lock relay and ground. See Fig 1 . See WIRING DIAGRAMS  . Is the resistance less than 5 ohms? If yes, then go to next step. If not, then repair Black wire between power door lock relay and ground.
  6. Check Power Door Lock Switch

    Access power door lock switch in drivers door. See DOOR LOCK SWITCH  under REMOVAL & INSTALLATION. Put door lock switch in UNLOCK position. As you unlock the door, measure the resistance between the Green/Black wire and the Green/Red wire at the connector. See Fig 1 . See WIRING DIAGRAMS  . As you lock the door, measure the resistance between Green/Black wire and the Blue/Red wire at the connector. Is resistance less than 5 ohms for both switch positions? If yes, then go to next step. If not, then replace power door lock switch.
  7. Check lead To Power Door Switch

    Access power door lock relay. Measure the resistance of the Green/Red wire, Green/Black wire and the Blue/Red wires between the power door lock relay and the power door lock switch. See Fig 1 . See WIRING DIAGRAMS  . Are the resistances less than 5 ohms? If yes, then go to next step. If not, then repair faulty circuit.
  8. Check Power Door Lock Relay

    Check power door lock relay for proper operation. See POWER DOOR LOCK RELAY  under COMPONENT TESTS. Replace relay if faulty. If relay operates as specified, go to next step.
  9. Check Supply To Power Door Lock Motor

    Turn the ignition switch to OFF position. Access power door lock motor. See DOOR LOCK MOTOR  under REMOVAL & INSTALLATION. Measure the resistance of the Green and Red wires between the power door lock relay and the power door lock motor. See Fig 1 . See WIRING DIAGRAMS  . Are the resistances less than 5 ohms? If yes, then go to next step. If not, then repair faulty circuit.
  10. Check Power Door Lock Motor

    Turn the ignition switch to ON position. Unlock and lock the faulty door lock. Did the door lock unlock and lock as directed? If yes, then system is operating correctly at this time. See SYMPTOM INDEX  table for additional symptoms. Replace faulty motor if operation is not as specified. See DOOR LOCK MOTOR  under REMOVAL & INSTALLATION.
Fig 1: Identifying Power Door Lock Motor, Relay & Switch Terminal
G00138983Courtesy of FORD MOTOR CO.