Driver Controls and Instruments cab is 70°F (21°C) or higher. During cold weather, the heater can be operated at the same time, to prevent discomfort. 1 2 3 1 2 1. If the cab is hot inside, temporarily open the win- dows to let the hot air out. 3 2. Move the air conditioning on/off lever to the off po- sition, and turn the fan switch off before starting the engine. 3. Start the engine. 5 4 01/19/2000 f830368b 1. Fan Switch 2. Air Selection Switch 3. Temperature Control Switch 4. Air Source Lever at the Fresh Air Position 5. AC On/Off Lever at the On Position 4. Move the air conditioning on/off lever to the on po- sition. Then select fresh or recirculated air with the air source lever.
IMPORTANT: If the outside air is dusty or smoky, set the air source lever at recirculated air and keep the windows and vent closed, to prevent drawing in dust or smoke. Fig. 3.37, Air Conditioning Settings 5. Move the temperature control switch counterclock- wise for cool air. In this position, no heat is given off by the heater. 8. If the air from the vents is too cold, move the tem- perature control switch clockwise for warmer air flow. 6. Turn the fan switch to the highest speed. See Fig. 3.37 . IMPORTANT:
To prevent the buildup of fumes or odors inside of the cab (for example, from smok- ing), do not operate the heater and air conditioning system with the air source lever in the recirculation mode for more than 20 minutes. 7. As soon as cool air is flowing from the dashboard outlets, close the windows. Adjust the fan switch setting as desired. 3.49