A/C Refrigerant System, Checking Cooling Performance

A/C Refrigerant System Troubleshooting

A/C Refrigerant System, Checking Cooling Performance

• A/C Evaporator Temperature Switch (E33) (if equipped) switches A/C compressor OFF only in special instances so evaporator does not ice up; variable displacement A/C compressor maintains temperature of 0°C (32°F) in evaporator.

Test Conditions

• A/C refrigerant system fully charged

• A/C Clutch (N25) and compressor function OK

• Condenser and radiator clean and free of obstructions

• Air distribution can be adjusted properly

• Wiring OK as per wiring diagram

• Outside (ambient) temperature 20° C-30° C (68°F-86°F)

Checking

- Start engine.

- Set temperature control to maximum "cold".

- Press A/C button and select second blower speed.

- Adjust air distribution to instrument panel outlets.

- Insert thermometer into center instrument panel outlet.

- Raise engine speed to approximately 1500 RPM.

Specified Result

With normal humidity and outside (ambient) temperature between 20°-25°C (68°-77°F), system is sufficiently charged if air temperature from center instrument panel vent drops below 10°C (50°F) within one minute.

For higher ambient temperatures and/or higher humidity, specified air temperature from center instrument panel vent can be slightly higher.