TM 9-2320-386-10 3-16 MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION Table 3-1. Troubleshooting (Contd). 35. POWER PLANT HEATER FAILS TO START WHEN RUN-OFF-START SWITCH IS HELD IN START POSITION WARNING Exhaust gases can kill. Do not operate power plant heater in closed area occupied by personnel. Doing so may result in injury to personnel. CAUTION Do not operate fuel burning personnel heater and power plant heater at the same time. Doing so may result in overworked electric fuel pump. NOTE If RUN-OFF-START switch is turned to RUN posi- tion before red indicator light illuminates, heater will not operate. Step 1. Press PRESS-TO-TEST button on heater control box to check opera- tion of circuit. If red indicator light does not illuminate, notify unit maintenance. Step 2. Check fuel level on fuel gauge. Fill fuel tank if necessary. Step 3. Check to see if power plant heater shutoff cock is closed (para. 2-4). Open power plant heater shutoff cock. NOTE Select HI position if engine is cold. Select LO position if engine is already well heated. When in HI position, heater will automatically change to LO position when coolant temperature exceeds 190°F (88°C), and auto- matically change to HI position when coolant temper- ature drops below 120°F (49°C). 36. HEATER FAILS TO CONTINUE BURNING Check fuel level on fuel gauge. Fill fuel tank if necessary.