Table 1. Cab Heating, Air Conditioning, and 12 Volt Power Inverter Troubleshooting Procedures - Continued.
TEST OR INSPECTION
11. Monitor and record low pressure
A/C Performance Test OK - Remove
Will Not Engage - Con-
and high pressure gauges.
A/C Refrigerant Reclaimer. Trouble-
A/C Performance Test Not OK -
Repeat troubleshooting from the
N OT E
5. No Power From 12 Volt
Power Inverter Or +12
Always inspect the harness connectorsthat are involved in the circuit.
Volt Auxiliary Port
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-
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.
Diagnostic Code Not Active - Pro-
ceed to Test Step 2.
Test Step 2. Test 12 Volt Power
Inverter Battery Supply Circuit
1. Turn ignition switch and battery
disconnect switch to the OFF
position (TM 5-3805-293-10).
2. Remove 12 Volt power inverter
fuse F-37 (TM 5-3805-293-10)
from fuse panel.
3. Inspect for open fuse.
Fuse Open - Proceed to step 4.
Fuse OK - Install 12 Volt power
inverter fuse F-37 (TM 5-3805-293-
10) in fuse panel.
Proceed to Test Step 3.
4. Disconnect cab upper wiring har-
ness connector R-C23 (WP 0009,
Figure 277) from 12 volt power
inverter (WP 0009, Figure 278)