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Home >> Plymouth >> 1978 >> Arrow Base, Automatic Trans >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Auto. A/C Systems >> Testing >> System Calibration Test >> Servo Check

Servo Check

  1. With system "On" and in A/C mode, change tester lo park position. After voltmeter reading has dropped to zero, disconnect inboard electrical insulator (6-way) at serve assembly.
  2. Using an accurate ohmmeter, check resistance across the black and violet wires at servo (see Figure). Resistance should be between 200 and 1500 ohms.
  3. If resistance is not within tolerance, replace servo. If resistance value is OK, continue with test of amplifier.