1. Verify that there is no continuity between antenna feeder terminals A and B using an ohmmeter.

2. Inspect for continuity between the antenna feeder terminals using an ohmmeter.

Front antenna feeder inspectionMazda 6 Service Manual: Lane Departure Warning
If the system determines that the vehicle may deviate from its lane, the lane
departure warning (beep sound, rumble sound*1, or steering wheel vibration) is activated
and the direction in which the system determines that the vehicle may deviate is
indicated in the multi-information display and ...
Mazda 6 Service Manual: Door switch removal/installation
Front
1. Disconnect the negative battery cable.
2. Remove in the order indicated in the table.
3. Install in the reverse order of removal.
Rear
1. Disconnect the negative battery cable.
2. Remove in the order indicated in the table.
3. Install in the reverse order of removal. ...