TM 5-3805-291-23-1
TROUBLESHOOTING WITHOUT A DIAGNOSTIC CODE - CONTINUED
0008 00
Table 8. AC System Troubleshooting - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. If low pressure gage reading is normal,
System Only Cools Cab in 1. Check low and high pressure gage
3.
(gage reading may drop into vacuum
during operation of AC.
Morning and in Evening
range during testing procedure) and
Not During Hot Part of Day.
high pressure gage reading is normal
Air Flow is Very Cold but
and is below normal when low pressure
Air Flow Becomes Warm.
gage drops into vacuum range, go to
Test 2.
2. If readings are not as specified, exit this
test.
2. The system has a large amount of
1. Recover refrigerant (WP 0225 00) and
replace inline dryer (WP 0224 00).
moisture. Desiccant in receiver/dryer
Evacuate and charge system with
or inline dryer is full of water. Water is
correct amount of refrigerant. Measure
released during high ambient
refrigerant by weight (WP 0225 00).
temperatures. Ice collects in orifice and
ice can block flow of refrigerant.
2. After system is charged, operate for a
minimum of 10 minutes (TM 5-3805-
291-10) and perform Performance
Checks for AC System (WP 0018 00) to
verify correct operation of AC system.
N OT E
4.
High Pressure (Liquid Line)
is Very Hot. Compressor
The compressor is not operating under ambient temperatures that are
May Become Noisy and
extreme. Compressor is not operating under high humidity that is extreme.
Drive Belt May Slip.
1. Check low and high pressure gage
1. If low pressure gage reading is above
during operation of AC.
normal and high pressure gage reading
is above normal, go to Test 2.
2. If readings are not as specified, exit this
test.
2. The system is overcharged.
1. Recover refrigerant (WP 0225 00) and
replace inline dryer (WP 0224 00).
Evacuate and charge system with
correct amount of refrigerant. Measure
refrigerant by weight (WP 0225 00).
2. After system is charged, operate for a
minimum of 10 minutes (TM 5-3805-
291-10) and perform Performance
Checks for AC System (WP 0018 00) to
verify correct operation of AC system.
Check non-return valve for proper
5.
Water is in Vents and
positioning and direction.
Leaking From Unit.