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Amplifier Calibration (Programmer Removed)

  1. Remove programmer cover and make the following connections: Plug male connector of suitable tester (J-23713) electrical harness into programmer. Plug tester electrical connector into female connector of tester electrical harness. Place dummy plug from tester onto programmer rotary valve, connect it to vacuum, and adjust to 20 in. Hg (minimum). Connect 12 volt battery positive lead to yellow wire from electrical test connector and battery negative lead to test connector black wire.
  2. Voltmeter on tester should read 12 volts when in "#2 FEED" position, "#7 LO RELAY" position, and "#8 AUTO RELAY" position. If not, check for strong voltage supply and good connections.
  3. Using a screwdriver, slip shaft of feedback potentiometer, turning shaft fully counterclockwise (gear does not move). Vacuum motor should now be in full heat position. Place manual/automatic switch in "MANUAL". Rotate manual control to "MAX HEAT". Carefully adjust manual control to "180" (exactly).
  4. Slip shaft of feedback potentiometer very slowly clockwise, looking for signs of vacuum motor mechanism movement (do not watch output shaft). Stop adjustment when movement first occurs.
  5. Check adjustment with manual control: Rotate control to "MAX HEAT", watching for signs of vacuum motor mechanism movement while slowly rotating control back to "180". First movement should occur exactly at "180". Make fine adjustments required to meet specified "180" position.
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