1. Disconnect the negative battery cable.
2. Remove the washer tank. (See WASHER TANK REMOVAL/INSTALLATION)
3. Connect battery positive voltage to the terminal B and ground to the terminal A of the motor.
4. Verify that the rear washer motor operates.

Rear washer motor removal/installation
Rear wiper motor removal/installationMazda 6 Service Manual: Rocking the Vehicle
WARNING
Do not spin the wheels at more than 56 km/h (35 mph), and do not allow
anyone to stand behind a wheel when pushing the vehicle: When the vehicle
is stuck, spinning the wheels at high speed is dangerous. The spinning tire could
overheat and explode. This could cause serious injuries.
...
Mazda 6 Service Manual: Excessive Speed Warning
If the vehicle speed exceeds the speed limit sign displayed on the active driving
display, the warning sound is activated and the area around the speed limit sign
displayed on the active driving display flashes 3 times in amber, and if the vehicle
speed continues to exceed the displayed speed ...