Programmer Adjustment
- With programmer installed on module and retained with 3 screws, check for proper alignment of programmer with air delivery nozzle.
- Apply 10-15" Hg to ports "2" and "3" of the rotary valve. Connect a vacuum gauge to port "4" and seal all other ports.
- At the terminal connectors, apply a 12-volt source to terminal "1". Connect terminal "2" to ground. Watch for the programmer to move to maximum heat position.
- Now, preload the air-mix door in maximum heat position by pulling the threaded rod at top of module. Pull with 22 ft. lbs. to insure proper door seal.
- Snap threaded rod into plastic retainer on programmer output arm. Do not disturb programmer or door position while engaging rod.
- Release pulling force on air-mix door. Connect ground to terminal "3" (with 12 volts still applied to terminal "1") through a 33-ohm resistor. Programmer should now set to maximum A/C position.
- Check for vacuum output on port "4" and for proper sealing of air-mix door against frame. If necessary, repeat adjustment.
Courtesy of GENERAL MOTORS COMPANY