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: Power Windows
The ignition must be switched ON for the power windows to operate.
WARNING
Make sure the opening is clear before closing a window: Closing a
power window is dangerous. A person's hands, head, or even neck could be caught
by the window and result in serious injury or even death. This warning ap ...
Mazda 6 Service Manual: Rear seat disassembly/assembly
4SD
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
5HB
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
...