TM 9-2350-247-10
OPERATE ENGINE COOLANT HEATER KIT (M548A3) — Continued
0041 00
CAUTION
Overheating will damage the batteries. Don’t use the engine coolant heater if the temperature is
above -25
F (-32
C). Make sure both manual shutoff valves are open before you start the heater.
If coolant doesn’t flow, the heater will be damaged.
5.
Hold RUN-OFF-START switch to START until indicator light comes on. Then move switch straight to RUN without
stopping in the OFF position.
NOTE
When the switch is at HI, the heater will automatically transfer to low heat if coolant
temperature reaches 190
F (88
C), and will switch back to high heat if coolant temperature
drops to 120
F (49
C). If coolant should reach 245
F ±15
F (118
C ±9
C), the heater will stop
automatic-ally and must be restarted manually.
6.
Select high or low heat with the hi-lo switch. The heater will always start on low heat no matter how the hi-lo switch is
set, and will go to high after it starts if the switch is at HI.
7.
If heater doesn’t start, try again. If it doesn’t start in three tries, troubleshoot it (WP 0055 00).
CAUTION
To avoid discharging batteries, do not operate lights, radios, or other electrical equipment for
very long while coolant heater is running. Always turn off heater and close coolant shutoff valve
(inlet) before you start engine.
NOTE
The heater will stop burning right away, but the combustion air blower will run until the heater
is purged of fuel and the burner is cool. The indicator light will stay on until the blower stops.
Close the coolant shutoff valve (inlet) by turning the handle clockwise whenever you stop the
heater.
8.
If you don’t operate carrier after 12 hours of running engine coolant heater, run the engine until batteries are charged.
Stop coolant heater while the engine is running. Keep fuel tank full.
0041 00-3
