TM 9-2320-209-34-2-3 FRAME 2 1. Put control switch (1) in OFF position. Put HI-LO switch (2) in LO position. Fill coolant container (3) with coolant. 2. Take off end cover plate (4). Refer to para 21-6c, frame 6. 3. Inspect inside of heater (5) for coolant leaks. If leaks are found, stop testing. Take heater (5) apart. Refer to para 21-6c. 4. Connect power supply lead (6) to plus (+) battery terminal (7). Connect ground lead (8) to minus (-) battery terminal (9). END OF TASK 21-10