TM-9-2320-280-10 HMMWV Operator Manual Download
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TM 9-2320-280-10 (3) The NBC heaters (6) supply heated air to protective mask facepieces connected to the GPFU system. Five heaters are installed in the M996 and M996A1 ambulances; three in the patient compartment and two in the cab. Seven heaters are installed in the M997, M997A1, and M997A2 ambulances; five in the patient compartment and two in the cab. When the heater (6) is not in use, the protective cap (9) should be installed in the heater (6) outlet. The cap (9) is a one- way check valve allowing air to flow in only one direction, outward from the heater (6). This reduces the potential risk of NBC contamination to the vehicle's NBC system. The heater (6) is activated by turning the temperature control knob (8) clockwise and adjusting to the desired heat level. The indicator light (7) will illuminate when the heater (6) is in operation (4) The NBC control box (11) is mounted in the cab above and behind the passenger position. It houses the control switch (13) for the system and a fuse panel (12). A diagram (15) on the control box (11) shows heater location and identifies the fuse responsible for each heater circuit (16). Spare fuses are also present. (5) To replace a NBC fuse (10), simply pull it straight out of the fuse panel (12). Check fuse (10) for an open fuse element or a melted fuse link (14). If the fuse (10) is damaged, replace with a new fuse (10). All fuses in the NBC control box are 20 amp. 2-215