Heating and Air Conditioning: Service and Repair

WARNING:
- REVIEW SAFETY PRECAUTIONS AND WARNINGS BEFORE CHARGING THE REFRIGERANT SYSTEM.
- AVOID BREATHING A/C REFRIGERANT AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY IRRITATE EYES, NOSE AND THROAT. USE ONLY APPROVED SERVICE EQUIPMENT MEETING SAE REQUIREMENTS TO DISCHARGE R-134a SYSTEM. IF ACCIDENTAL SYSTEM DISCHARGE OCCURS, VENTILATE WORK AREA BEFORE RESUMING SERVICE.
- R-134a SERVICE EQUIPMENT OR VEHICLE A/C SYSTEM SHOULD NOT BE PRESSURE TESTED OR LEAK TESTED WITH COMPRESSED AIR. MIXTURE OF AIR and R-134a CAN BE COMBUSTIBLE AT ELEVATED PRESSURES. THESE MIXTURES ARE POTENTIALLY DANGEROUS AND MAY RESULT IN FIRE OR EXPLOSION CAUSING INJURY OR PROPERTY DAMAGE.

CAUTION:
- Do not overcharge refrigerant system, as excessive compressor head pressure can cause noise and system failure.
- A small amount of refrigerant oil is removed from the A/C system each time the refrigerant system is recovered and evacuated. Before charging the A/C system, you MUST replenish any oil lost during the recovery process. Refer the equipment manufacturer instructions for more information.

The procedure below should be used to fill the refrigerant charge in the air conditioning system. This A/C system does not have or use a sight glass to check or charge the system.

After the system has been tested for leaks and evacuated, a refrigerant (R-134a) charge can be injected into the system.

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.

1. If using a separate vacuum pump close all valves before disconnecting pump. Connect manifold gauge set to the A/C service ports.

NOTE: Always refer to the underhood HVAC Specification label for the refrigerant fill level of the vehicle being serviced.

2. Measure refrigerant. Refer to the instructions provided with the equipment being used.
3. Verify engine is shut off. Open the suction and discharge valves. Open the charge valve to allow the refrigerant to flow into the system. When the transfer of refrigerant has stopped, close the suction and discharge valve.
4. If all of the charge did not transfer from the dispensing device, put vehicle controls into the following mode:
- Automatic transmission in park or manual transmission in neutral
- Engine at idle
- A/C mode control set to outside air
- A/C mode control set to panel mode
- A/C temperature control set to full cool
- Blower motor control set on highest speed
- Vehicle windows closed
If the A/C compressor does not engage, test the compressor clutch control circuit and correct any failure.

5. Open the suction valve to allow the remaining refrigerant to transfer to the system.

WARNING: TAKE CARE NOT TO OPEN THE DISCHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.

6. Close all valves and test the A/C system performance.
7. Disconnect the charging station or manifold gauge set. Install the service port caps.

REFRIGERANT CHARGE CAPACITY

2004 Ram Gas 0.728kg (1.604 lbs.)
2004 Ram Diesel 0.850kg (1.873 lbs.)