Connect battery positive voltage to terminal A and ground to terminal B of the blower motor and verify its operation.

Blower motor removal/installation
Resistor removal/installationMazda 6 Service Manual: Scheduled Maintenance (U.S.A., Canada, and Puerto Rico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following
conditions (severe driving conditions) apply.
Repeated short-distance driving
Driving in dusty conditions
Driving with extended use of brakes
Driving in areas where salt or other corrosive materials are used
...
Mazda 6 Service Manual: Hold switch removal/installation
1. Disconnect the negative battery cable.
2. Remove the console.
3. Disconnect the connector and remove the HOLD switch terminals. (See
SELECTOR LEVER DISASSEMBLY/ASSEMBLY.)
4. Remove the selector lever knob component.
5. Remove the HOLD switch.
6. Install the HOLD switch to selector lever k ...