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: Units
Conversion to SI Units (Système International d'Unités)
All numerical values in this manual are based on SI units. Numbers shown
in conventional units are converted from these values.
Rounding Off
Converted values are rounded off to the same number of places as the SI
unit value ...
Mazda 6 Service Manual: Keys
WARNING
Do not leave the key in your vehicle with children and keep them in a place
where your children will not find or play with them: Leaving children in a
vehicle with the key is dangerous. This could result in someone being badly injured
or even killed. Children may find these keys to be ...