TM 9-2320-386-10 2-116 2-48. OPERATION OF SWINGFIRE HEATER (Contd) (10) If overheating switch (2) is not in OPERATION position, allow swingfire heater (5) to cool. Place overheating switch (2) in OPERATION position. Operate swingfire heater (5) (task b), close access door (3), and install catch (6). If swingfire heater (5) will not operate, notify unit maintenance. WARNING Box assembly and exhaust pipe will become hot after continued operation. Be careful when opening access door and when removing swingfire heater. Failure to do this may result in injury to personnel. (11) After operation, raise catch (6) and open access door (3). Do not allow skin to contact box (1) if hot. Open door (4) (refer to paragraph 2-45), loosen wingnut (9) by turning counterclockwise, and remove swingfire heater (5). Do not allow skin to contact exhaust pipe (7). (12) Install swingfire heater (5) in mixing pipe (refer to task c.), water jacket (refer to task e.), or stow (refer to task f.), as necessary. e. Operation of Water Jacket. (1) General. Swingfire heater is installed in water jacket to heat engine coolant and battery compartment to permit easy starting in arctic conditions. (2) Open wingnut (9) all the way counterclockwise. (3) Make sure gasket (8) is flat against body of swingfire heater (5). NOTE • Water jacket is located on right side of vehicle under fender. • Make sure swingfire heater is installed with pump lever straight up. • Swingfire heater should be in operation when installed. Refer to task b. of this paragraph. (4) Remove cap (11) and install swingfire heater (5) in water jacket (10). Tighten wingnut (9) by turning clockwise. 1 2 3 4 5 6 7