Checking the Capacity And Function Of the Air Conditioning System
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
Compressor
In principle there are three reasons for a compressor not starting:
- a fault in the magnetic clutch.
- incorrect pressure in the system (too low or too high).
- fault in the wiring or the compressor control system.
Performance Test
The performance test provides an indication of the air conditioning system capacity. During the test the temperature of the air flowing out of the center dashboard vents is measured under predetermined conditions (engine speed (RPM), fan speed, control settings etc).
If the capacity is too low this may be due to a number of "external" reasons, for example
- slipping compressor drive belt.
- insufficient air flow to the condenser (blocked by insects/dirt, foreign objects).
- poor engine cooling fan (FC) function.
- insufficient air flow to the climate control system (duct blocked by leaves etc).
- poor blower fan function.
- incorrectly adjusted control/damper/water valve for airflow - recirculation - temperature.
Too low capacity can also be caused by "inner" causes (faults in the system).
Initially this is checked by:
- visual check (damage, leakage. In the event of leakage there is often excess oil = greasy surface).
- listening (there is always a little noise in the system when the refrigerant changes between gas and water form at different pressures).
- feeling the components (if there is cold/warm air, how cold/hot they are).
- measuring the pressure in the system (if possible measurements should be taken on both the low and high pressure sides).