Alarm Going Off ..and other daft question!!!!

[malcolm_jamesuk]

A quick question please .... the alarm on my 97 2.0l 16v has gone off a couple of times now ( it is the standard factory fit ) seems to do it in the early hours of the morning and always when its getting very cold ( there has never been anyone around ) .. could it be the battery dropping voltage .....or do these alrms not sence that ??? Also sounds daft what is the small black device .. "thing" that is stuck to the top of the windscreen ( now im not talking about the mirror before the "sarky" answers poor in ha ha ) that has a wire coming off of it that disapears of into the roof lining .. its to the left of the rear view mirror near the top.

Many thanks regards Malc

[johnny_adidas]

an ariel of some sort?

[Stupink]

Yeah.
Probably an aftermarket alarm ariel. thats a common install place for them.

For the alarm trigger try reading the codes. go to <a href="http://www.topbuzz.co.uk" target="_blank">www.topbuzz.co.uk</a> if you dont know how and read the how to read the ecu fault codes guide. then use pins A and H instead of A and B. and watch the LED on the drivers pillar ultrasonic for the flashes.
18 Fault with disarm signal
32 Boot caused an alarm condition
33 Bonnet caused an alarm condition
34 Doors caused an alarm condition
35 Ignition Turned on caused an alarm condition
36 Imbolization circuit open circuit
37 Radio caused an alarm condition
38 Ultrasonic's caused an alarm condition
39 Fault with disarm signal. (central locking fuse blown)
46 Rear Window smashed caused an alarm condition ('92+ models only)
52 Horn Voltage Low Horn O/C or fuse blown

[Col]

<!--QuoteBegin-malcolm_jamesuk+--><div class='quotetop'>(malcolm_jamesuk)</div><div class='quotemain'><!--QuoteEBegin-->A quick question please .... the alarm on my 97 2.0l 16v has gone off a couple of times now ( it is the standard factory fit ) seems to do it in the early hours of the morning and always when its getting very cold ( there has never been anyone around )<!--QuoteEnd--></div><!--QuoteEEnd-->

mine did the same a couple of times a few weeks ago when it was really cold. never done it before and has been fine since ?!

[malcolm_jamesuk]

Thanks for the replys guys will look into it and keep u posted.

[johnny_adidas]

dya know mine did it in supermarket a couple of times last nite for no apparent external reason. i put it down to one of two things. either the fact i had left the roof light on by mistake or my seatbelt retainer thingy had been slowly sliding back down into place. prob not much help to you doh.

[Stupink]

I don't know if you are all aware, but the most common thing is leaving the airvents open in windy conditions, it sets the internal sensors off.

[johnny_adidas]

jesus never knew dat!! d wind will set it off but thievin ****rs wont!! great!!

[malcolm_jamesuk]

thanks not very "tetchy" these alarms are they ......

[Dan Willis]

<!--QuoteBegin-Stupink+--><div class='quotetop'>(Stupink)</div><div class='quotemain'><!--QuoteEBegin-->I don't know if you are all aware, but the most common thing is leaving the airvents open in windy conditions, it sets the internal sensors off.<!--QuoteEnd--></div><!--QuoteEEnd-->

That would explain a lot. All my Cavaliers and Calibras have done that.

[Stupink]

I can't say i've paid much attention, but you press the button or something to disable the internal sensors i think.. so worth trying that a few times to see if it cures it. you'll still have the door sensors etc etc working.

[imcsherry]

Was it windy when the alarm went off or had the car interior been very hot when you locked it up? If so try shutting the heater vents as belive it or not sometimes air movement cfrom wind can trigger them or when a car cools from very hot the air movement again can set it off.

[malcolm_jamesuk]

the car had sat stationary four quite a while as the alarm has been going off - 3ish in the morning... last driven around 6pm so sat for a good 9or so hours....suppose could be wind but i dont remember it being particularly windy ... mainly pretty cold as i went running out in my "kegs" though..............

[malcolm_jamesuk]

Had a chat with the local alarm specialist he recons that as the alarm has been going off after the car has been left stationary for 6-9 hours at a time it is more likely to be the battery.......

what do you all think ??

he recons that the system senses voltage drops and if the battery drops too low too quickly then would go off ...!!???