TM 9-2320-363-34- 1
With the engine running and the air
conditioner and blower on, both
terminals will show voltage when the
compressor should be engaged; one
terminal will show voltage when the
compressor should be disengaged.
If there is no voltage, there is a
problem in the electrical system from
the batteries to the thermostatic
switch. Check all circuits for the
cause, and repair or replace the wiring
compressor is not engaging and
disengaging properly, the thermostatic
switch is the cause. Replace it with a
6. Shut down the engine and, to prevent
accidental electric shock or shorting during
dash assembling, disconnect the batteries.
7. Assemble the dash.
A restricted suction line causes low suction
pressure at the compressor and little or no
cooling. A restriction in a line between the
compressor and the expansion valve can cause
high discharge and low suction pressure, and
Usually, areas of ice or frost build-up mean a
blockage. Parts that often freeze up are probably
corroded or inoperative and should be replaced.
Parts (such as the expansion valve) that freeze up
once in a while may do so because of moisture in
the system, which will cause the moisture
indicators element to turn white or pink; if this
recover the refrigerant
evacuate/recycle the system refrigerant, replace
the receiver-drier,and install a new charge.