2-31. HEATER/DEFROST OPERATION
a. Operate Cab Heat.
Heat output increases as HEAT control is pulled farther out.
(1) Pull HEAT control (1) to desired setting.
(2) Position FAN switch (2) to desired speed.
(3) Pull AIR control (3) to allow outside air to enter cab for ventilation.
(4) Push in AIR control (3) to stop flow of outside air.
(5) Push in HEAT control (1) to turn off heat.
(6) Position FAN switch (2) to OFF to turn off fan.