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On vehicle With Engine Off

  1. Partially remove speedometer cluster so access to speed sensor is possible. For cluster removal, see appropriate story in SWITCHES, GAUGES & SPEEDOMETERS  in this section.
  2. Turn ignition on and cruise control dash switch to either "CRUISE" or "AUTO". Connect voltmeter between ground and terminal 2 (Black) on speed sensor 3-wire connector. Note and record voltage reading. Reading should be greater than 10 volts but less than battery voltage.
  3. Connect voltmeter between ground and terminal 3 (Red) on sensor connector. Voltage should be one to two volts less than at terminal 2. This is the voltage drop through the light emitting diode.
  4. Connect voltmeter between ground and terminal 1 (Green) of sensor connector. Roll car forward (approximately six feet) while checking voltage. Two voltage peaks should occur in the distance the car travels. This is the photo transistor output.
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