1. Inspect for resistance between the front door speaker terminals using an ohmmeter.


2. To verify that the front door speaker outputs sound, apply voltage to the front door speaker and release using a 1.5-V battery.
Front door speaker removal/installation
Rear door speaker removal/installationMazda 6 Service Manual: Electrical parts
Battery cable
Before disconnecting connectors or removing electrical parts, disconnect
the negative battery cable.
Wiring Harness
To remove the wiring harness from the clip in the
engine room, pry up the hook of the clip using a
flathead screwdriver.
...
Mazda 6 Service Manual: Rear View Monitor Operation
The operation of the rear view monitor when reversing the vehicle varies depending
on the traffic, road, and vehicle conditions. The amount of steering and the timing
also varies depending on conditions, so confirm the surrounding conditions directly
with your eyes and steer the vehicle in acc ...