Durango 4WD V8-5.9L VIN Z (1998)
Evaporator Core: Customer Interest
A/C System - Cooling Performance Deterioration
NUMBER: 24-11-99
GROUP: Heating & A/C
DATE: June 25, 1999
SUBJECT:
A/C Cooling Performance Deteriorates After A Few Minutes Of Operation
OVERVIEW:
This bulletin involves adjusting the temperature control cable or installing a new A/C Evaporator
MODELS:
1998 - 1999 (AN) Dakota
1998 - 1999 (DN) Durango
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH AIR CONDITIONING.
SYMPTOM/CONDITION:
A/C cooling performance deteriorates after a few minutes of operation.
DIAGNOSIS:
WARNING:
EYE PROTECTION MUST BE WORN WHEN SERVICING THE AIR CONDITIONING REFRIGERANT SYSTEM. TURN OFF (ROTATE
CLOCKWISE) ALL VALVES ON THE EQUIPMENT BEING USED BEFORE CONNECTING TO OR DISCONNECTING FROM THE
REFRIGERANT SYSTEM. FAILURE TO OBSERVE THESE WARNINGS MAY RESULT IN PERSONAL INJURY.
NOTE:
THE AIR TEMPERATURE IN THE TEST ROOM AND IN THE VEHICLE MUST BE A MINIMUM OF 21° C. (70° F.) FOR THIS TEST.
1.
Connect a tachometer and a manifold gauge set to the vehicle.
2.
Set the heater-NC mode control switch knob in the recirculation mode (Max-A/C) position, the temperature control knob in the full cool position,
and the blower motor switch knob in the highest speed position. On Durango models with rear NC, set the rear A/C blower control knob to the
OFF position.
3.
Start the engine and hold the idle at 1000 rpm with the compressor clutch engaged. Refer to the appropriate Service Manual, Group 24, Diagnosis
and Testing section if the compressor clutch does not engage.
4.
During the test, the engine should be at operating temperature, the doors and windows closed, and the hood mostly closed.
5.
Insert a thermometer into the driver side center A/C (panel) outlet.
6.
With the compressor clutch engaged, record the panel outlet temperature every 30 seconds for at least five minutes. The temperature should drop
at least 20° F. below the ambient temperature within the first 60 seconds of operation. The temperature should continue to drop. After five
minutes, the outlet temperature must be at or below those listed in the Performance Temperature and Pressure Chart identified in Group 24 of the
appropriate Service Manual.
7.
If the suction pressure meets the requirements listed in the Performance Temperature and Pressure Chart identified in Group 24 of the appropriate
Service Manual, record the outlet temperature reading. Clamp off both heater hoses (inlet and outlet). Wait five minutes and record the
temperature again. Compare the second reading to the list in the Performance Temperature and Pressure Chart. If the temperature is now within the
appropriate ranges, the temperature control cable must be adjusted. Refer to the appropriate Service Manual, Group 24, Adjustment section.
8.
If the panel outlet temperature began to rise after two - three minutes of operation and eventually levels off at ambient temperature or, the suction
pressure drops to 13 psig or less, or the clutch disengages and begins to cycle, perform the Repair Procedure.
PARTS REQUIRED:
AR (1)
05015440AA
Coil, Evaporative, Durango Models
