TM 9-4120-395-14&P
4-40. HEATER THERMOSTAT.
This task covers:
a. Inspection
b. Testing
c. Removal
d. Installation
INITIAL SETUP:
TooIs:
Tool Kit, service, refrigeration unit
Equipment Conditions:
Power off at power source.
General Safety Instructions:
Disconnect input power to the unit before performing any internal maintenance.
Voltages used can kill. Shutting the unit off at the thermostat does not disconnect
unit power.
a.
Inspection.
(1) Remove the three screws (1, Figure 4-36) and lift off the heater access door (2) on the upper right side
of the air conditioner.
(2) Check the wiring and heater thermostat (3) for damage and loose mounting screws (4).
(3) Replace the heater access door (2) and secure with the three screws (1).
b.
Testing.
(1) Remove the three screws (1, Figure 4-36) and lift off the heater access door (2) on the upper right side
of the air conditioner.
(2) Use the multimeter to check the thermostat (3). An open or direct short to ground indicates a defective ther-
mostat which must be replaced.
(3) Install the heater access door (2) and secure with the three screws (1).
c.
Removal.
(1) Remove the three screws (1, Figure 4-36) and lift off the heater access door (2) on the upper right side
of the air conditioner.
(2) Tag and remove the wires on the heater thermostat (3).
(3) Remove the two screws (4) and lift out the heater thermostat.
d.
Installation.
(1) Place the heater thermostat (3, Figure 4-36) Into position in the heater assembly (5) and secure with the
two mounting screws (4).
(2) Connect the wires as marked and remove the tags.
(3) Install the heater access door (2) and secure with the three screws (1).
4-67
