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Speedometer Inoperative (Van)

  1. Disconnect vehicle speed sensor buffer. Turn ignition on. Check for voltage between Brown wire ground. If voltage is less than battery voltage, check for open or short in Brown wire.
  2. If battery voltage is present, check for voltage between Pink/Black and Black/White wires. If voltage is less than battery voltage, check for open or short in Black/White wire. If voltage is okay, raise and support vehicle. Start engine and shift transmission into drive.
  3. Check for AC voltage between Purple/White and Light Green/Black wires of vehicle speed sensor buffer. If AC voltage is not present, check for opens in Purple/White and Light Green/Black wires.
  4. If wires are okay, replace vehicle speed buffer. If AC voltage is present between Purple/White and Light Green/Black wires, check for AC voltage between Light Green/Black and White wires.
  5. If voltage is not present, replace vehicle speed buffer. If voltage is present, check for AC voltage between Yellow and Black/White wires. If voltage changes with RPM, replace digital ratio adapter.
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