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Home >> Buick >> 1979 >> Skyhawk Base, Automatic Trans >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Auto. A/C Systems - Automatic Climate Control >> Testing >> Automatic Climate Control System Functional Test >> "AUTO" - Dial @ 85

"AUTO" - Dial @ 85

Blower speeds should drop and discharge air temperature should increase. Depending on temperature in work area, air delivery mode should change from A/C outlets to heater outlets.

SYSTEM OPERATION CHART

SYSTEM RESPONSE
  BLOWER SPEED AIR INLET DOOR POSITION TEMPERATURE DOOR POSITION MODE DOORS POSITION DEFROSTER DOOR POSITION COMPRESSOR HTR-WATER SHUT-OFF VALVE IS BLOWER DELAYED FOR ENGINE WATER WARM-UP?
CONTROL LEVER SETTINGS OFF FIXED LOW 5.0V - HTR 4.5V - A/C OUTSIDE AIR VARIES - RESPONSIVE TO SENSORS FORCED TO HEATER SEALED DOESN'T OPERATE USUALLY OPEN - EXC. CLOSED AT MAX. A/C POSITION OF PROGRAMMER NO - BLOWER IS TURNED ON BY O'RIDE SW.
ECON. VARIABLE BLOWER PROGRAM EITHER HEATER, BI-LEVEL OR A/C DEPENDS PROGRAMMER POSITION DOOR WILL ASSUME "BLEED" POSITION AFTER 45 SECOND DELAY AND WILL DELIVER BLEED AIR TO W/S IF IN HEATER OR BI-LEVEL MODE YES - SAME CONDITIONS AS IN "AUTO"
LO FIXED LOW 5.0V - HTR 4.5V - A/C OPERATES ABOVE APPROX. 37° (3°C) NO - BLOWER IS TURNED ON BY O'RIDE SW.
AUTO VARIABLE BLOWER PROGRAM RECIRCULATE AIR WHEN PROGRAMMER IS AT MAX. A/C - OTHERWISE OUTSIDE AIR YES - EXCEPT WHEN CAR INTERIOR IS WARM, IN WHICH CASE IN-CAR SWITCH ON CONTROL HEAD TURNS BLOWER ON IMMEDIATELY. EVEN IF ENGINE IS COLD.
HI FIXED HI 13.5V
BI LEVEL VARIABLE BLOWER PROGRAM BI-LEVEL OPEN
DEF FIXED HI 13.5V FORCED TO HEATER FULL OPEN TO W/S NO - BLOWER IS TURNED ON BY O'RIDE SW.