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: Front buckle removal/installation
1. Perform the following procedure for vehicles with seat belt warning.
(1) Disconnect the negative battery cable.
(2) Remove the front seat.
(3) Disconnect the buckle switch connector.
2. Perform the following procedure for vehicles without seat belt warning.
(1) Remove the console.
...
Mazda 6 Service Manual: Relay inspection
Relay Type
Four-terminal
Type A
1. Remove the relay.
2. Inspect for continuity between the relay terminals using an ohmmeter.
If not as specified, replace the relay.
Type B
1. Remove the relay.
2. Inspect for continuity between the relay terminals using an ohmmeter.
If not as ...