OM3017.3 Operation - Section 3 Instrument Panel and Indicator Lights Page 3-29 (60, Figure 3-8) HEATER TEMPERATURE CONTROL LEVER (63, Figure 3-8) AIR CONDITIONER CONTROL (OPTIONAL) The heater temperature control lever is provided for the operator to select a comfortable temperature. The far left position turns heat off for warm weather operation (or air conditioning if so equipped). Milder temperatures can be regulated by moving the control lever to the right. Moving the control lever to the far right selects the warmest temperature for cold weather operation. The Air Conditioner control lever is moved from left (off) to right to cool the cab air. Full right position is coldest setting.
(61, Figure 3-8) DEFROSTER/HEAT CONTROL LEVER (64, Figure 3-8) FAN CONTROL KNOB The fan control knob is provided to control the cab air fan motor. The fan motor is a 3-speed motor (low, me- dium and high) which are selected by rotating the control knob clock- wise to the desired position. "Off" position is marked by symbol on panel. The defroster/heater control lever permits the operator to select either defroster or heater. Moving the control lever to the far left position directs heated air to the cab floor for most efficient heating of cab air. (65, Figure 3-8) AIR CLEANER SERVICE VACUUM GAUGE Moving the lever to the far right selects the defroster function.
This directs heated air to the windshield. The air cleaner service gauge(s) provides a continuous reading of maximum air cleaner restriction reached during operation. The air cleaner(s) should be serviced when the gauge(s) shows the following maximum recommended restric- tion: Selecting a center position for the control lever divides the air to both floor heat and defroster. (62, Figure 3-8) OUTSIDE/INSIDE AIR CONTROL LEVER 20 inches of H 2 O vacuum for Detroit Diesel en- gine. 25 inches of H 2 O vacuum for Cummins engine. The outside/inside air control lever is connected to a vent, which allows either outside or inside air to be circulated through the cab heater assembly.
After service, push the reset pin on face of gauge to allow gauge to reset to zero. When truck is equipped with a CUMMINS engine of LESS THAN 2000 HP (1491 kW), instrument panel will contain only two (2) Air Cleaner Service gauges. Moving the lever to the left directs outside air to be circulated through the heater assembly. (66, Figure 3-8) FUEL LEVEL GAUGE (OPTIONAL) Moving the lever to the right directs inside air to be recirculated through the heater assembly. Allows operator to be aware of fuel status without viewing fuel tank at ground level.