Connect the J 39500-B .

Are the pressures greater than the specified values?

350 kPa (50 psi)

Go to Step 2

Go to Step 6

Inspect and correct for a blown Air Conditioner (A/C) fuse.

Does the complaint persist?

Go to Step 3

System OK

Inspect and correct for the following conditions:

Refer to HVAC Compressor Clutch Does Not Engage . Does the complaint persist?

--

Go to Step 4

System OK

Inspect and correct for the following conditions:

Refer to Engine Cooling.

Does the complaint persist?

--

Go to Step 5

System OK

1. Read the DCS for Bulletins and Hints.
2. Follow the procedures indicated.

Does the complaint persist?

--

Go to Step 8

System OK

1. Add 0.453 kg (1 lb) of refrigerant.
2. Perform a leak check. Refer to Leak Testing .

Did you find a leak?

--

Go to Step 7

System OK

1. Repair the leak.
2. Inspect the system performance. Refer to System Performance Test .

Does the complaint persist?

--

Go to Step 1

System OK

Perform an A/C Performance Check using the following steps:

1. Ensure that the ambient temperature is at least equal to the specified value.
2. Ensure that the engine is idling at normal operating temperature.
3. Turn the A/C to the ON position.
4. Select the coldest setting.
5. Select the MAX blower speed.
6. Record the A/C pressures.
7. Record the A/C temperatures.
8. Refer to System Performance Test .

Does the A/C performance meet the requirement on the Performance Chart?

5°C (41°F)

Go to Step 9

Go to HVAC High Side vs. Low Side Pressure Chart

Was the customer complaint made due to high temperature and/or high humidity?

--

Go to Step 10

System OK

Perform a leak test. Refer to Leak Testing .

Did you find a leak?

--

Go to Step 11

System OK

Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Does the complaint persist?

--

Go to Step 8

System OK

Important: The V5 clutch may cycle if the discharge pressure exceeds 2758 kPa (400 psi).

Improper condenser operation

Improper condenser operation may result from one of the following causes:

High side refrigerant restriction

1. Feel liquid line before expansion tube (orifice). A cold line indicates restriction in the high side.
2. Inspect for a frost spot in order to locate the restriction.
3. Repair the line as necessary.

Refrigerant system overcharged (high discharge and high suction pressures)

The clutch may cycle ON/OFF and cause compressor noise. Refer to air in system.

Expansion tube (orifice) blocked

Low suction pressures.

Air in system (High discharge and high suction pressures).

1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
2. Inspect the expansion (orifice) tube for blockage. Refer to Expansion (Orifice) Tube Replacement . Clean or replace the tube as required.
3. Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
4. Leak test the system. Refer to Leak Testing .

The compressor is damaged internally.

The expansion tube (orifice) is missing.

Feel the liquid line after the expansion tube. If the line is warm, recover the refrigerant. Refer to Refrigerant Recovery and Recharging . Inspect the system for proper installation of the expansion tube. Refer to Expansion (Orifice) Tube Replacement . If the expansion tube or the O-ring is missing, replace the expansion tube.

The compressor runs at minimum stroke.

The compressor control valve is set improperly.

The low load test creates a low cooling load that causes the V5 compressor to go toward a minimum stroke. Minimum stroke is necessary in order to evaluate the control valve set point. Perform the low load test using the following procedure:

1. Start the engine.
2. Run the engine at a fast idle.
3. Open the hood.
4. Close the windows and the doors.
5. Set the A/C controls to LOW blower and MAX cooling.
6. Record the test results.
7. Evaluate the test results as follows:

•	If suction pressure is 25-35 psi, the control valve is functioning properly.

•	If the suction pressure is outside the limits of 25-35 psi, replace the control valve.

The refrigerant system is undercharged.

1. The refrigerant may be undercharged when the suction pressure is below 35 psi during the high load test.
2. The suction line before the accumulator will be warm if the charge is low.
3. Add 1 lb of refrigerant.
4. Recheck the pressure. Verify that the pressure is in the white area on the chart. Then find and correct the leak.
5. Recover and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

The expansion tube (orifice) is blocked.

1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
2. Inspect the expansion (orifice) tube for blockage. Refer to Expansion (Orifice) Tube Replacement . Clean or replace as required.
3. Evacuate the system to a vacuum. Improper evacuation of the system prior to recharge will cause air to remain in the system.
4. Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
5. Leak test the system. Refer to Leak Testing .