GMC 1982 Light Duty Truck Service Manual page 48

C O N D I T I O N E D A I R IS D I R E C T E D T H R U W/SHLD,
I P. & F L O O R D I S T R I B U T O R O U T L E T S
C O N D I T I O N E D A I R IS D I R E C T E D T H R U I P. O U T L E T S
IN T H IS M O D E L E V E R POSITION, M A X I M U M
C O O L I N G IS O F F E R E D WITH THE C O N D I T I O N E D
A I R D I S T R I B U T E D T H R U I P O U T L E T S AT
A N Y B L O W E R SPEED.
4 SPEED F A N
C O N T R O L L E V E R
V A C U U M O P E R A T E D S Y S T E M
S E L E C T O R (M O D E ) L E V E R
A N O N C O M P R E S S O R O P E R A T IN G P O S IT IO N ,
W IT H O U T S ID E A I R D E L I V E R E D T H R U I P. O U T L E T S
A N O N CO M P R E S SO R O P E R A T IN G P O S IT IO N ,
W I T H O U T S ID E A IR D I S T R I B U T E D A B O U T
80% TO F L O O R & 20% TO W /S H L D
T E M P E R A T U R E L E V E R P O S IT IO N R E G U L A T E S T E M P E R A T U R E
OF THE A I R E N T E R I N G THE P AS S E N G E R C O M P A R T M E N T BY
C A B L E O P E R A T I O N OF THE H E A T E R CORE T E M P E R A T U R E D O O R
C O N D I T I O N E D A IR
D I S T R I B U T E D A B O U T
80% TO W / S H L D
TO F L O O R