Car Alarms: MAZDA3 SP5 ALARM PROBLEM, dash area, mazda3

Question
QUESTION: The alarm of my car gets activated when the car is placed under the sun, specially if it is a very hot day. It never happens when the car is inside the garage or under a shade. It has been checked twice and nothing shows. Also when this happens, the light on the roof turns on and stays on at least ten minutes after the alarm is deactivated and the car is running. So I turn it off, turn on the car, drive it, and ten minutes later the light is still on.

ANSWER: Describe the sounds and the lights that the
alarm makes so I can tell what's happening,
and the year of the truck please.

A.

---------- FOLLOW-UP ----------

QUESTION: The car is a Mazda3 SP5 2006 (liftback)The sound is from the horn which is the regular sound these alarms make. The light is the cabin light on the roof that you can turn on and off manually.

Answer
Odd circuit malfunction. But there is no real
reason accept maybe an overheated circuit board
triggering the light, which drains the battery
enough to trigger the factory system. The sensor
may me in the dash area.
Experiment. Cover any suspected sensor in the dash
with black electrical tape, and see if that changes
anything. if not. then I have no way to help
with out inspection.

Let me know.

A