Refrigerant System Charge

This test can be accomplished using a manifold gauge set or a DRB scan tool.
1. Connect a manifold gauge set to discharge side of compressor or connect a DRB or equivalent scan tool to Diagnostic Link Connector (DLC) and set scan tool to "Partial Charge Test."
2. Attach a clamp on thermocouple part No. P.S.E. 66-324-0.014 or equivalent onto liquid line as close to condenser outlet as possible, to observe liquid line temperature.
3. With transaxle in Park, engine idling at 700 RPM and windows open, set air conditioning controls as follows:
a. Controls set to "Outside Air."
b. Panel mode to full cool.
c. Blower on high.
d. A/C button in the ON position.

4. Operate system for a couple of minutes to allow system to stabilize.
5. Set system pressure to about 260 psi, by blocking off airflow to front grill area. This will maintain a constant pressure and stop the cooling fans from alternating between high and low speeds.
6. When using a manifold gauge set, proceed as follows:

Fig. 13 Charge Determination Graph:

a. Observe discharge pressure and liquid line temperature and, using graph shown, determine where the system is currently operating.
b. If system is in undercharged region of graph, add two ounces of refrigerant to system and recheck readings.
c. If system is in overcharged region of graph, drain two ounces of refrigerant from system and recheck readings.
d. Repeat steps "b" and "c" until readings are within proper operating range.

7. When using a DRB or equivalent scan tool, it is not necessary to use a graph. Scan tool will calculate correct liquid line temperature automatically.