Alarm going off in cold/freezing weather

[David A]

Folks, the alarm on the maser spyder has an annoying habit of going off overnight when the temperature drops below freezing (well that seems to be common factor - I've not put a thermometor out!)

My first thoughts are battery voltage drop when it gets cold- but it seems to have stacks of power in the mornings even in cold weather (i.e. quick turnover of engine etc)

Any ideas?

Cheers

Dave

[Le TVR]

I've seen something similar where moisture gets into the bonnet/door switches and when it freezes the ice just pushes the contacts open.
Could be something like that?

[wazza]

How long has the alarm been on the car?

[David A]

wazza said:

How long has the alarm been on the car?

Since it left the factory - factory fit alarm going off.

[wazza]

I used to work in the car security industry.

In my experience, factory installed alarms once they are a few years old are extremely difficult (or impossible) to repair. You could try looking at the bonnet, boot and door switches as a cost effective attempt to rectify the fault.

Many years of climatic and temperature changes can play havoc with an old alarm. Problem could lie with corrosion or a dry joint on the alarm's circuit board.

Most main dealers will struggle to diagnose an alarm fault without calling in an autoelectrician or alarm installer to assist. (And charge you a big whack in the process).

My advice is to find a good local sparky. If all else fails, a new alarm system may be your only option.