Car alarm keeps triggering (Cobra 7925)

[Mathew J. Newton]

Hi all,

I appear to be having some problems with the Cobra 7925 alarm fitted
to my Hyundai Coupe in that occasionally the alarm triggers for no
apparent reason - obviously there is one but quite what I don't know.
Incidentally, the alarm beeps 4 times when disarming after a trigger -
is this number significant i.e. indicating which senser trigger the
alarm?

The sensors for this alarm include contact switches on the doors,
bootlid and bonnet and also a pair of ultrasonic transducers inside
the car.

All wiring etc seems fine so I am naturally suspecting the
ultrasonics.

The previous owner said it used to set off when windy (this may be a
red herring though) although this morning when I heard/saw it it was
definitely not windy.

However, the car was parked in the sun - could that have anything to
do with it? Have I just answered my own question?

Is it likely to be the ultrasonics given the possible (coincidental?)
link between it being windy/sunny and the alarm going off? Can the u/s
sensitivity be reduced on these alarms?

After reading a similar query/response in another group I was going to
try closing the air vents when leaving the vehicle but unfortunately
the alarm does not trigger that often for this to be particularly
conclusive...

All tips, suggestions etc welcome.

Many thanks,

Mathew

[David M Johnson]

The 4 alarm beeps is telling you what "zone" is being set off..it
probably flashes the parking lights the same number of times while disarmed.
Usually when you disarm and get 3 beeps it means that the doors,trunk, or
hood was tripped. I am not quite sure what Ultrasonic tranducers are...what
country are you in? If they are glass break sensors, I know that the older
ones would be set off by the natural sonics coming from the glass when they
heated up or cooled down. If they are a "shock" sensor then perhaps it just
needs to be calibrated. Or if it is a microwave sensor it may also need to
be calibrated. I know on my Alpine alarm if I lose battery power I have to
go and reset my glass breaks, my shock, and my microwave sensors afterwards.
Have you tried going and setting the alarm off yourself? You might be able
to narrow down by violating the zone and it reporting it after disarm. Open
one of your doors while the alarm is armed, and see what it beeps after you
disarm. Try doing the same on the hood, and the trunk or hatch. You should
be able to narrow down what is failing. Some manufactures seperate the
Hood/Trunk pins from the door pins for carjacking features so it would be a
good idea to trip all of those sensors. On my alarm 3 beeps is doors, 4
beeps is Hood/Trunk 5 beeps is shock 6 beeps is Microwave and 7 beeps is
glass break. Try it out and let me know

Dave

"Mathew J. Newton" <googl...@newtonnet.co.uk> wrote in message
news:2bbdbdc0.02040...@posting.google.com...

[Mathew J. Newton]

"David M Johnson" <m_3...@yahoo.com> wrote in message
news:zy7r8.1023$c02.1...@news.uswest.net...

Thanks Dave for the detailed response.

I'll give the testing you suggested a try. I managed to get hold of the UK
importers and they are sending a copy of the instruction manual which may
help!

Cheers,

Mathew