Chevrolet 1980 Light Duty Truck Service Manual page 31

Fig. 1 A -2 -H e a te r Control-C-K M odels
outlet air is dependent of the ratio of heated to unheated
air (controlled by the temperature door).
CONTROLS
Heater controls for CK & G Models are shown in
Figures 1A-2 and 1A-3.
HEATER
1A-3--Heater Control-G Models
Fig.
1A-3
LIG H T T R U C K SER V IC E MANUAL