TM 5-3805-293-23-2
0022
Table 1. Cab Heating, Air Conditioning, and 12 Volt Power Inverter Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
N OT E
4. Refrigerant Compressor
Will Not Engage
Always inspect the harness connectorsthat are involved in the circuit.
Poor connections can often be the cause of a problem in an electrical
circuit. Verify that all connections in the circuit are clean and secure,
and that all connections are in good condition. If a problem with a con-
nection is found, correct the problem and verify that this diagnostic code
is Active before performing this procedure.
Perform open or short circuit test ateach harness connection to identify
correct harness to replace.
Perform this test only if condition is active.
This test assumes the A/Csystem is fully charged.
Test Step 1. Check for Active Diag-
nostic Codes.
1. Connect MSD (WP 0006), select
Diagnostic Code Active - Trouble-
Trans/Chassis 120M and check
shoot diagnostic code first before pro-
for active diagnostic codes.
ceeding.
Diagnostic Code Not Active - Pro-
ceed to Test Step 2.
Test Step 2. Test HVAC Controller.
1. Turn HVAC blower to maximum
HVAC Blower Motor Turns ON - Pro-
speed (TM 5-3805-293-10) and
ceed to Test Step 3.
verify HVAC blower turns on.
HVAC Blower Motor Does Not Turn
ON - Diagnose HVAC blower motor
first. Refer to HVAC Blower Does Not
Turn On In One or More Speeds in
this work package.
Test Step 3. Test Refrigerant Com-
pressor Clutch, Relay, Voltage and
Ground Circuits
1. Disconnect rear air conditioning
wiring harness connector AW-C2
(WP 0009, Figure 261) from
refrigerant compressor clutch
solenoid (WP 0009, Figure 260)
(WP 0098).
2. Disconnect rear air conditioning
wiring harness connector AW-C3
(WP 0009, Figure 265) from
refrigerant compressor arc sup-
pressor (WP 0009, Figure 264)
(WP 0098).
0022-26
