1. Remove the climate control unit.
2. Inspect for continuity between the fan switch terminals using an ohmmeter.


Climate control unit inspection
Defroster switch inspectionMazda 6 Service Manual: Foot Brake
This vehicle has power-assisted brakes that adjust automatically through normal
use.
Should power-assist fail, you can stop by applying greater force than normal
to the brake pedal. But the distance required to stop will be greater than usual.
WARNING
Do not coast with the engine stalled or t ...
Mazda 6 Service Manual: No.9 noise while operating a/c system
Diagnostic procedure
* : If there is gas leakage, air enters into the A/C system. The desiccant
within the receiver/drier absorbs the moisture from the air and becomes
saturated. If the A/C system is used in this condition, the inside of the A/C
compressor will begin to rust due to this ...