Because the antenna system is equipped with a capacitor, the continuity cannot be checked. Therefore proceed the following simple inspection.
Turn the AM radio on.
Tune to the frequency that there is no broadcast and you will hear a buzzing sound.
Turn a work light on and shake it around the antenna rod. (around 10—20 mm {0.40—0.78 in})
CAUTION:
Use a fluorescent light type for the inspection. Accurate diagnostic cannot be done with a different type of light.

If a whirring sound from the speaker synchronized to the work light movement is confirmed, the antenna system is normal.
Coil Antenna Removal/Installation
Entertainment Personalization Features Setting ProcedureStop Vehicle in Safe Place Immediately
If any of the following warning lights turns on, the system may have a
malfunction. Stop the
vehicle in a safe place immediately and contact an Authorized Mazda Dealer.
...
Windshield Defrosting and
Defogging
Press the windshield defroster switch.
In this position, the outside air position
is automatically selected, and the air
conditioner automatically turns on. The
air conditioner will directly dehumidify
the air to the front windshield and side
windows (on ). Airflow
amount will be increased. ...
License Plate Light Removal/Installation
1. Disconnect the negative battery cable..
2. Remove the lens..
3. Insert a tape-wrapped fastener remover to the position shown in the figure,
release the tabs.
4. Pull the rear bumper in the direction of the arrow (1) in the figure, and
pull out the license plate lights in the directi ...