Antenna Feeder No.3 Inspection
1. Disconnect the negative battery cable..
2. Remove the rain sensor cover. (Vehicles with auto light/wiper system).
3. Disconnect the rain sensor connector. (Vehicles with auto light/wiper system)
4. Partially peel back the seaming welts.
5. Remove the following parts:
a. Sunroof seaming welt (vehicles with sunroof)
b. A-pillar trim.
c. Front scuff plate.
d. Rear scuff plate.
e. B-pillar lower trim.
f. Upper anchor of the front seat belt.
g. B-pillar upper trim.
h. Rear seat cushion.
i. Tire house trim.
j. C-pillar trim.
k. Map light.
l. Sunvisor.
m. Assist handle.
n. Headliner.
6. Disconnect the antenna feeder No.5 and connector..
7. Verify that the continuity between antenna feeder No.3 terminals is as indicated in the table.

If not as indicated in the table, replace antenna feeder No.3.

1. Disconnect the negative battery cable..
2. Remove the rain sensor cover. (Vehicles with auto light/wiper system).
3. Disconnect the rain sensor connector. (Vehicles with auto light/wiper system)
4. Partially peel back the seaming welts.
5. Remove the following parts:
a. Sunroof seaming welt (vehicles with sunroof)
b. A-pillar trim.
c. Front scuff plate.
d. Rear scuff plate.
e. B-pillar lower trim.
f. Upper anchor of the front seat belt.
g. B-pillar upper trim.
h. Rear seat cushion.
i. Tire house trim.
j. Trunk side upper trim (5HB).
k. C-pillar trim.
l. Map light.
m. Sunvisor.
n. Assist handle.
o. Headliner.
6. Disconnect the connector.

7. Verify that the continuity between antenna feeder No.3 terminals is as indicated in the table.

If not as indicated in the table, replace antenna feeder No.3.

With audio unit (with display)
1. Disconnect the negative battery cable..
2. Remove the rain sensor cover. (Vehicles with auto light/wiper system).
3. Disconnect the rain sensor connector. (Vehicles with auto light/wiper system)
4. Partially peel back the seaming welts.
5. Remove the following parts:
a. Sunroof seaming welt (vehicles with sunroof)
b. A-pillar trim.
c. Front scuff plate.
d. Rear scuff plate.
e. B-pillar lower trim.
f. Upper anchor of the front seat belt.
g. B-pillar upper trim.
h. Rear seat cushion.
i. Tire house trim.
j. Trunk side upper trim (5HB).
k. C-pillar trim.
l. Map light.
m. Sunvisor.
n. Assist handle.
o. Headliner.
p. Liftgate upper trim.
6. Disconnect the antenna feeder No.5 and connector..
7. Disconnect the antenna feeder No.7..
8. Verify that the continuity between antenna feeder No.3 terminals is as indicated in the table.

If not as indicated in the table, replace antenna feeder No.3.

Test yourself
A quick Mazda 3 quiz: every answer comes with an explanation and a link to the manual page.