A/C Refrigerant System Cooling Performance, Checking

A/C Refrigerant System Cooling Performance, Checking


NOTE: 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" (if Manual A/C) or "LO" (if Climatronic).
- Manual A/C: press A/C button and select second blower speed.
- Climatronic: Select minimum blower speed (manual override) by pressing "decrease blower speed" button (observe front "blower speed" display in control head)
- 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.