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Home >> Mercury >> 2009 >> Mariner Base, 2.5 7, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 140 (Rear View Mirror) >> Diagnostic Tests >> Rear View Mirrors >> Pinpoint Tests >> Pinpoint Test A: The Mirrors are Inoperative

Pinpoint Test A: The Mirrors are Inoperative

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Power Mirrors for schematic and connector information.

Normal Operation 

The exterior mirror control switch is supplied voltage from the central junction box (CJB) through circuit 1523 (DG) and ground through circuit 57 (BK). The exterior mirror control switch activates the LH exterior mirror up and down positions by switching voltage and ground on circuits 940 (DB/OG) and 945 (YE/BK). The exterior mirror control switch activates the LH exterior mirror left and right positions by switching voltage and ground on circuits 942 (RD/OG) and 945 (YE/BK). The exterior mirror control switch activates the RH exterior mirror up and down positions by switching voltage and ground on circuits 943 (VT/OG) and 945 (YE/BK). The exterior mirror control switch activates the RH exterior mirror left and right positions by switching voltage and ground on circuits 944 (DG/OG) and 945 (YE/BK). The exterior mirror control switch must be in the appropriate (left or right) position for the desired mirror to operate.

This pinpoint test is intended to diagnose the following:

PINPOINT TEST A: THE MIRRORS ARE INOPERATIVE 

  1. A1 CHECK THE VOLTAGE TO THE EXTERIOR MIRROR CONTROL SWITCH 
    • Key in OFF position.
    • Disconnect: Exterior Mirror Control Switch C527
      • Fig 1: Checking Exterior Mirror Control Switch Voltage
      GF0013042Courtesy of FORD MOTOR CO.
    • Measure the voltage between exterior mirror control switch C527-4, circuit 1523 (DG), harness side and ground.
    • Is the voltage greater than 10 volts? 
    1. YES  : Go to  A2.
    2. NO  : VERIFY the CJB fuse 2 (7.5A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation.
  2. A2 CHECK CIRCUIT 57 (BK) FOR AN OPEN 
      Fig 2: Checking Circuit For Open
      GF0013043Courtesy of FORD MOTOR CO.
    • Measure the resistance between exterior mirror control switch C527-8, circuit 57 (BK), harness side and ground.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  A3.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
  3. A3 CHECK CIRCUIT 945 (YE/BK) FOR A SHORT TO VOLTAGE 
    • Key in ON position.
      • Fig 3: Measuring Voltage
      GF0046592Courtesy of FORD MOTOR CO.
    • Measure the voltage between exterior mirror switch C527-7, circuit 945 (YE/BK) harness side and ground.
    • Is voltage present? 
    1. YES  : REPAIR the circuit. TEST the system for normal operation.
    2. NO  : Go to  A4.
  4. A4 CHECK CIRCUIT 945 (YE/BK) FOR A SHORT TO GROUND 
    • Key in OFF position.
      • Fig 4: Measuring Resistance
      GF0046593Courtesy of FORD MOTOR CO.
    • Measure the resistance between exterior mirror switch C527-7, circuit 945 (YE/BK) harness side and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  A5.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
  5. A5 CHECK CIRCUIT 945 (YE/BK) FOR AN OPEN 
    • Disconnect: LH Exterior Mirror C516
      • Fig 5: Measuring Resistance
      GF0046594Courtesy of FORD MOTOR CO.
    • Measure the resistance between exterior mirror switch C527-7, circuit 945 (YE/BK) harness side and LH exterior mirror C516-2, circuit 945 (YE/BK) harness side.
    • Is the resistance less than 5 ohms> 
    1. YES  : INSTALL a new exterior mirror control switch. REFER to Exterior Mirror Control Switch . TEST the system for normal operation.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
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