2010 Mazda Mazda3 - Electrical glitch sets off alarm and more

Maintenance/Repairs
1

2010 Mazda 3 Sport GX Auto

Car alarm (lights, horn) goes off randomly, then stops (battery checked, all good). Also, door-ajar dash light and interior dome light will go on while driving - hitting door lock button with turn both off.

How do I fix this? I’ve just removed the horn fuse so at least it’s not annoying the neighbours, but the issue still occurs.

2

There is a malfunctioning door ajar switch. If the security module detects a door ajar while the alarm is set, the alarm will sound. Identify which door is causing the door ajar warning and replace that switch or door latch.

3

Concur, and it is probably the driver’s door switch that’s gone faulty.