1. Disconnect the negative battery cable.
2. Remove the dashboard. (See DASHBOARD REMOVAL/INSTALLATION.)
3. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
4. Remove the blower unit.

5. Install in the reverse order of removal.
Basic system
Blower unit disassembly/assemblyMazda 6 Service Manual: Sas unit configuration
1. Connect the SST (WDS or equivalent) to the DLC-2.
2. Input vehicle information following the directions on the screen.
3. Select Module programming.
4. Select Programmable module installation.
5. Select the following items and perform procedures according to directions
on the screen.
...
Mazda 6 Service Manual: Anti-theft system
Alarm Conditions
If the anti-theft system protection has been activated, any one of the
following conditions will trigger the system:
- Disconnected battery cable
- Discharged battery
- Disconnected audio unit connectors
If the system is triggered, the audio unit will then be ...