TROUBLESHOOTING WITHOUT A DIAGNOSTIC CODE - CONTINUED
Table 8. Air Conditioning System Troubleshooting - Continued.
TEST OR INSPECTION
2. The thermostat switch is held closed or Replace compressor as necessary (WP
there is a short in wire to magnetic
Cycle or Clutch Will Not
clutch and magnetic clutch will not
Disengage. Air Flow to
release. Check wire that goes to
Operator's Compartment is
magnetic clutch. Wire may have an
Very Cold or Air Flow May
be Restricted Completely at
Times - Continued.
N OT E
Compressor Clutch is
Engaged but System Has
A restriction in liquid line can be detected by running a hand along line until
there is a change in temperature. A change in temperature in line will usu-
ally indicate location of restriction.
1. Check for restriction.
(a) Check low and high pressure gage
(b) Start engine. Operate engine at
1,400 rpm. Move temperature
control knob to MAXIMUM
position and fan to HIGH position.
Close all windows and doors. In
order to stabilize system, operate
system for a minimum of 10
(c) Outlet on accumulator should be 1. If low side reading is above 50 psi (345
cold to touch. If outlet is not cold,
kPa), replace inline dryer (WP 0194
check readings on manifold gages.
2. If low side reading is into vacuum,
check for a plugged orifice tube or a
restriction in line (WP 0193 00).
3. If problem still exits, go to Test 2.
2. Check that system is properly charged
1. Recover refrigerant (WP 0191 00),
(WP 0191 00).
evacuate, and charge system with
correct amount of refrigerant. Measure
refrigerant by weight (WP 0191 00).
2. After system is charged, operate for a
minimum of 10 minutes (TM 5-3805-
290-10) and perform Performance
Checks for Air Conditioning System
operation of AC system.
3. If problem still exists, go to Test 3.
3. Check drive belt for damage or
1. If belt is loose or damaged, replace or
adjust belt (WP 0046 00) as necessary.
2. If problem still exists, go to Test 4.