TM 9-2320-361-10 2-57. OPERATION OF VAN BODY HEATER (PRIMARY AND SECONDARY) KITS (Contd) (4) Depress red indicator light (4) to check operation of circuit. If red indicator light (4) does not illuminate, notify your supervisor. (5) Set HI-LO switch (5) to HI (up) or LOW (down) position, depending upon heating needs. NOTE Ž RUN-OFF-START switch is spring-loaded and will return to OFF position from START position if not held down. Ž If red indicator light does not illuminate within two minutes, turn RUN-OFF-START switch to OFF position. Wait three minutes before trying to start heater again. If red indicator light does not illuminate after two attempts, notify your supervisor. (6) Turn RUN-OFF-START switch (6) down to START position. Hold in that position until red indicator light (4) illuminates. NOTE If RUN-OFF-START switch is turned to RUN position before red indicator light illuminates, heater will not operate. (7) As soon as red indicator light (4) illuminates, turn RUN-OFF-START switch (6) to RUN position, with no hesitation at OFF position. NOTE Blower motor will continue to run for one to three minutes after RUN-OFF-START switch is turned to OFF position. Red indicator light will remain on until fuel in heater burns away and heater cools. (8) After heater operation, turn RUN-OFF-START switch (6) to OFF position. (9) Place exhaust blower switch (8) in HIGH (up) or LOW (down) position as necessary to circulate fresh air into van body. 2-213