2002 T&C A/C cool down test?

[videomagician]

How do you get the cool down test to run on a 2002 T & C? I've tried the full blower/full cold/panel vents/hold down rear wiper + rear washer fluid combo and the lights never start blinking. So far all I've done is drain all my washer fluid.

The reason I started trying to do this is the A/C is not blowing cold air, it has refrigerant, and we replaced the battery a few months ago so I've read we need to recalibrate the system. TIA.

David

[donald7150]

here it is from the FSM:

DIAGNOSIS AND TESTING - A/C COOL DOWN TEST
The heater-A/C control module can perform an A/C cool down test, which is a test performed during the manufacturing process to confirm that the air conditioning system is performing satisfactorily. This test can also provide a quick confirmation of air conditioning system performance to the service technician. If the test is completed satisfactorily, no further service is required. If the test is failed, proceed to the A/C Performance Test to confirm the a/c system is operating properly, or use a DRBIIIŽ scan tool to diagnose the A/C system control and distribution systems. Refer to the appropriate diagnostic information.

MANUAL TEMPERATURE CONTROL
The front blower speed and rear blower speed (if equipped with rear HVAC) must be set to High and the evaporator temperature sensor must be greater than 55° F or the test will fail immediately. The test is activated by depressing the A/C and PWR buttons simultaneously and holding them depressed for no less than five seconds. The PWR and A/C LEDs will blink on and off until the test is complete. If the LEDs stop blinking before two minutes, then the cool down test has been completed successfully. If the two minutes expire without the expansion valve temperature reaching 20° F less than the outside air temperature, then the cool down test has been failed and further A/C system diagnosis is required. If the test is failed, the LEDs will continue to blink until the vehicle has been driven for greater than (8 miles).

AUTOMATIC TEMPERATURE CONTROL
The ambient air temperature in the room where the vehicle will be tested must be a minimum of 21° C (70°F) for this test. The test is activated by depressing the A/C and PWR buttons simultaneously and holding them depressed for no less than four seconds. The snowflake icon and the DELAY text in the ATC display will blink on and off alternately until the test is complete. If the snowflake icon and the DELAY text stop blinking before two minutes, then the cool down test has been completed successfully. If the two minutes expire without the evaporator temperature reaching 20° F less than the evaporator initial temperature, then the cool down test has been failed and further A/C system diagnosis is required. If the test is failed, the snowflake icon and the DELAY text will continue to blink across ignition cycles until the vehicle has been driven for greater than (8 miles).

[videomagician]

Thanks Donald,

That worked. Looks like I failed as my snowflake keeps blinking. :help:

Does it also say how to run the A/C Performance Test? I have the manual system.

Thanks again.

David

[donald7150]

The a/c performance test is a bit more complex, involves more than just pushing a couple of buttons

It involves monitoring the air temperature coming from the vents with a thermometer and using a pressure gauge set to monitor refrigerant pressures

but here is the procedure:

DIAGNOSIS AND TESTING - A/C PERFORMANCE TEST
An air conditioning performance test is the best way to determine whether the system is performing up to standard. This test also provides valuable clues as to the possible cause of trouble with the air conditioning system. The ambient air temperature in the location where the vehicle will be tested must be a minimum of 21° C (70°F) for this test.

WARNING: REFER TO THE APPLICABLE WARNINGS AND CAUTIONS FOR THIS SYSTEM BEFORE PERFORMING THE FOLLOWING OPERATION. (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - FRONT - WARNING - A/C PLUMBING) and (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - FRONT - CAUTION - A/C PLUMBING).


NOTE: When connecting the service equipment coupling to the line fitting, verify that the valve of the coupling is fully closed. This will reduce the amount of effort required to make the connection.

Connect a tachometer to monitor the engine speed.

Remove the caps from the refrigerant system service ports and attach a manifold gauge set to monitor the refrigerant system pressures.

Set the heater-air conditioner controls so that the compressor is engaged, the air within the vehicle is being recirculated, the output air is directed through the panel outlets, the temperature control is in the full cool position, and the blower motor is operating at its highest speed.

Start the engine and allow the engine to operate for about five minutes or until it reaches normal operating temperature. Then hold the engine speed at 1000 rpm with the compressor clutch engaged. If the compressor clutch does not engage, proceed with diagnosis of the compressor clutch coil. (Refer to 24 - HEATING & AIR CONDITIONING/CONTROLS - FRONT/COMPRESSOR CLUTCH COIL - DIAGNOSIS AND TESTING).

Close all the vehicle windows and doors.

Insert a thermometer in the left center panel outlet and operate the engine for five minutes.

With the compressor clutch engaged, record the left center panel outlet discharge air temperature, the discharge pressure (high side service port), and the suction pressure (low side service port). The compressor clutch may cycle, depending upon the ambient temperature and humidity. If the clutch cycles, use the readings obtained before the clutch disengaged.

Compare the discharge air temperature reading to the Performance Temperature and Pressure chart. If the temperature reading is high, check the refrigerant system for leaks and proper refrigerant charge level. (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - FRONT/REFRIGERANT - DIAGNOSIS AND TESTING - REFRIGERANT SYSTEM LEAKS) and (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - FRONT/REFRIGERANT - DIAGNOSIS AND TESTING - REFRIGERANT SYSTEM CHARGE LEVEL).

attached are the temperature and pressure specifications