A/C Pressure Chart and Compressor Diagnosis - Revision

89chrysler12

Models

1989 AC & AS Bodies Equipped With A/C and 3.0L Engine


Subject


Revision to Service Manuals - A/C Pressure Chart and Compressor Diagnosis


Index

HEATING AND AIR CONDITIONING


Date

August 28, 1989

No.

24-03-89 REVISION A

(C24-04-9)
P-3170
BODY CODE LEGEND

AC - DYNASTY/NEW YORKER/LANDAU AS - CARAVAN/VOYAGER/CARAVAN C/V


SERVICE MANUAL REVISION

This Technical Service Bulletin revises TSB 24-03-89 which should be removed from your files.

This bulletin covers a revision to the VARIABLE DISPLACEMENT A/C COMPRESSOR DIAGNOSIS CHART on pages 24-14 and 24-24 of the 1989 Front-Wheel-Drive Van/Wagon Service Manual, Publication # 81-370-9005 and on page 24-27 of the 1989 FrontWheel-Drive Passenger Car Service Manual, Publication # 81- 270-9002. It also describes a procedure to make the condenser fan operate continuously. THE ATTACHED PAGES SHOULD BE APPLIED OVER THE EXISTING PAGES IN YOUR SERVICE MANUALS.

The change involves a revised pressure chart to be used only when diagnosing variable displacement A/C compressor problems and should not be confused with charts used when making an overall A/C system performance test.

When using the new chart to check variable displacement compressors, the following test conditions must be observed:

- Refrigerant Charge Full (use sight glass)
- Ambient Temp. 70~F (21~C) or above
- Engine Speed 1000 rpm (use DRB II)
- A/C Control Settings A/C, recirculate, low blower
- Condenser Fan Running continuously (jumped)
- Doors and Windows Closed
- Gear Selector Park or neutral
- Parking Brake Set
- Rear Air Unit Off

FIGURE 1:

As indicated on the new A/C compressor diagnosis chart, the compressor is OK if the discharge (high side) pressures and the suction (low side) pressures intersect between zones one and two. Additionally, if the discharge pressure is above 180 psi, the compressor is good, regardless what the suction pressure is.

If the discharge pressure is above 180 psi when using the test conditions listed above, the variable displacement compressor will be in full stroke and will be acting like a fixed displacement compressor. Remember, above 180 psi the compressor is OK; i.e., it pumps.

The condenser fan may be made to run continuously by using a wire to jump the condenser fan switch connector located on the variable displacement compressor plumbing. See Figure 1.

To insure proper condenser fan operation after testing is completed, remember to reconnect the wiring harness connector to the condenser fan switch.


POLICY: Information only



24-14 HEATER AND AIR CONDITIONING



24-24 HEATER AND AIR CONDITIONING



HEATER AND AIR CONDITIONING 24-27