TM 9-4120-402-14
5-32. COMPRESSOR (B1). - continued
WARNING
Severe burns can result from touching hot heating elements. Do not touch heating element.
NOTE
The following steps apply to both compressors except as noted.
a.
Test.
(1)
Disconnect wiring harness at compressor connector J14 (located on junction box).
(2)
Carefully feel lower part of compressor.
(a)
If air conditioner has been connected to power supply for at least four hours, compressor should
feel warm (1000 to 120 ). If not warm, test crankcase heater for continuity.
F
(b)
If air conditioner has not been connected to power supply for at least four hours, compressor
temperature should be the same as surrounding air temperature.
(3)
pin F to pin G. Resistance should be 950 to 1450 ohms. Lower reading indicates short, and infinite
reading indicates an open.
*(4)
(a)
Remove compressor junction box cover.
(b)
Open connection between thermostat lead and heater lead.
(c)
Check heater continuity between open connection and J1 4-F.
If open, heater should be
replaced.
(d)
Check thermostat continuity between open connection and J14-G. If open, thermostat should be
replaced.
(5) Using multimeter, test compressor motor windings.
(a)
Check continuity between pins A, B, and C, and the compressor body. No continuity should
exist. If continuity exists, the compressor is bad.
(b)
Test 3 phase windings at J14 A to B, B to C, and A to C. All resistance readings should be
above zero and less than 2 ohms.
*(c)
Test resistance between pin D and pin E. Resistance should be zero indicating motor protector
is closed.
(d)
Compressor containing shorted, open or grounded winding or open motor protector, should be
replaced.
(e)
If compressor windings are bad, check for compressor burn out prior to installing a new
compressor. (See instructions in compressor removal.)
*Effective for Carrier Compressor only.
5-80