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: Dual proportioning valve replacement (without abs)
1. Remove in the order indicated in the table.
2. Install in the reverse order of removal.
Dual Proportioning Valve Installation Note
Install the dual proportioning valve so that the R mark faces the left side
of the vehicle.
...
Mazda 6 Service Manual: Bonnet switch inspection
Note
Bonnet switch has a built-in bonnet lock.
1. Open the bonnet.
2. Disconnect the negative battery cable.
3. Remove the radiator grille.
4. Disconnect the bonnet switch connector.
5. Check the continuity between the bonnet switch terminals A and B using an
ohmmeter.
If there is ...