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: To Operate the System
The High Beam Control System (HBC) operates to switch the headlights automatically
between high and low beams after the ignition is switched ON and the headlight switch
is in the AUTO and high beam position.
The High Beam Control System (HBC) determines that it is dark based on the brightness
...
Mazda 6 Service Manual: Towing
Proper lifting and towing are necessary to prevent damage to the
vehicle. Government and local laws must be followed.
A towed vehicle should have its front wheels off the ground. If
excessive damage or other conditions prevent this, use wheel dollies.
When towing with the rear wheels on ...