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Home >> Mercury >> 2008 >> Milan Base, 3.0 1, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 118 (Rear View Mirrors System -- F250-F550 Super Duty) >> Diagnosis And Testing >> 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 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

Test Step 

  1. A1 CHECK FOR POWER TO EXTERIOR MIRROR CONTROL SWITCH 
    • Disconnect: Exterior Mirror Control Switch C527.
    • Measure the voltage at exterior mirror control switch C527 pin 1, circuit 956 (OG/LG) harness side and ground.
      Fig 1: Measuring Voltage Exterior Mirror Control Switch C527 Pin 1, Circuit 956 (OG/LG) Harness Side And Ground
      G03925314Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 

    Result / Action to Take 

    • Yes  : GO to A2.
    • No  : REPAIR the circuit. TEST the system for normal operation.
  2. A2 CHECK CIRCUIT 542 (YE) FOR SHORT TO GROUND 
    • Measure the resistance to ground at the exterior mirror control switch C527 pin 6, circuit 542 (YE) harness side and ground.
      Fig 2: Measuring Resistance To Ground Exterior Mirror Control Switch C527 Pin 6, Circuit 542 (YE) Harness Side And Ground
      G03911292Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    • Yes  : GO to A3.
    • No  : REPAIR the circuit. TEST the system for normal operation.
  3. A3 CHECK CIRCUIT 542 (YE) FOR AN OPEN 
    • Disconnect: LH Exterior Mirror C521.
    • Measure the resistance between exterior mirror control switch C527 pin 6, circuit 542 (YE) and LH exterior mirror C521 pin 2, circuit 542 (YE) harness side.
      Fig 3: Checking Circuit 542 (YE) For Open
      G03925316Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    • Yes  : GO to A4.
    • No  : REPAIR the circuit. TEST the system for normal operation.
  4. A4 CHECK THE EXTERIOR MIRROR CONTROL SWITCH GROUND 
    • Measure the resistance to ground at exterior mirror control switch C527 pin 5, circuit 57 (BK) harness side and ground.
      Fig 4: Measuring Resistance To Ground Exterior Mirror Control Switch C527 Pin 5, Circuit 57 (BK) Harness Side And Ground
      G03911294Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    • Yes  : INSTALL a new exterior mirror control switch. TEST the system for normal operation.
    • No  : REPAIR the circuit. TEST the system for normal operation.