General

General

When fault-tracing, the ambient temperature must be at least 18 °C or higher.
There is always noise when the Air Conditioning (A/C) system is running. The reason for this is that the refrigerant changes phase between gas and liquid at different pressures.
The Air Conditioning (A/C) system pump (compressor) produces a soft buzzing noise.
The A/C compressor will start when the engine is started, even if the air conditioning A/C button is in the OFF position. After a few seconds the Air Conditioning (A/C) compressor will stop.
The above noises are normal operational noises from the Air Conditioning (A/C) system.
This fault-tracing describes partially how to locate and correct abnormal noise from the Air Conditioning (A/C) system, such as low frequency rumble or metallic/mocking, and partly how to fault trace and correct function problems.

WARNING: Follow the safety instructions for working with refrigerant

After performing this procedure, check the drive belt.