Hello

I'm having alarm issues with my 2008 Mazda 6 for a few years now. After a lot of research I realise this is a common complaint with people encountering similar symptoms to myself.

• The alarm went off at various times, but I saw a slight trend to the morning or evening when the temperature dropped or started to rise. Though, I'm not discounting I just noticed it more at those times as we, like our neighbours tended to be woken up by it.
• The original battery started to die around the time this started happening. I replaced the battery and from memory things improved.
• About 18 months later the new battery was also dying.
• Due to a lack of use, I regularly locked the card and disconnected the battery until the next time I needed to use it.
• I've fitted another new battery a couple of months ago and although the alarm has gone off once, I started locking the car with the key rather than the fob and parking in the other direction and it hasn't happened since. Though the weather has also changed in the that time. I also remember trying this before, but I thought previously the alarm still went off.
• Due to the batteries actually 'dying', I'm guessing there must be a slow drain somewhere on the car. I've taken the car to an auto-electrician and he couldn't find a drain that is likely to cause the issue, he says a small drain is expected with the alarm and other electronics. He did mention that there could be an occasional drain, which short of testing the car many times he wouldn't be able to trace easily.

My theory from my own experiences and other peoples issues is one of the following:

• Dodgy alarm -> draining battery
• Dodgy 'something' -> draining battery -> setting alarm off
• Dodgy door, boot, bonnet closure/sensor -> setting alarm off -> draining battery - (Possible with the air pressure within the car moving the door/boot/bonnet ever-so slightly)
• A series of dodgy batteries (unlikely)

I reach somewhere that you could see the last thing that set off your alarm. I purchased a fault code reader (Topdon AL400), but I couldn't find this or see any faults with the car. I'm not discounting that I just done it wrong or for some reason my reader doesn't support how these are stored, so was wondering if anyone could confirm if this is possible or not please?

The other thing is that I was thinking is about testing the drain myself. From research, it suggests disconnecting the negative lead and test between the lead and the terminal. Is this right? If I try this, is there anything I need to look out for please?

Thanks for taking the time reading this, and any help or assistance would be appreciated.