Alarm chirping randomly and A/C light blinking 2004 Camry


We have a Toyota 2004 Camry and it has the following problems, which the dealer wants to charge 98.00 “each” to just check it.

Here are the problems:

1. When we park in our garage at home with the car turned off, we can hear the random “alarm” chirping (the sounds that you open the car door with remote). It is very random, it went off every couples of hours. We did not check whether the doors become unlocked when the sound went off.

2. Sometime, the A/C light went blinking, typically accompanied with less or no cool air coming out. Typically, this will go away after a while, or when we drive it next time. I read on the internet, which basically said there are two possibilities:

(1) the cabin air filter is dirty, simply clean or replace it; (2) the compressor is bad (or a relay is bad).

We are wondering whether anyone have an idea what the problems may be and whether we really need to fix it.

Thank you very much for the help.

Regarding problem #2:
When was the cabin air filter last replaced?

The solution to the problem could be as simple as replacing this filter if it has been in there longer than specified in the maintenance schedule.