A couple of questions.

[Saxman]

Ok guys, I've got a couple of alarm related questions.

I have a facelift 06 Vectra C estate and have been having alarm related problems for a few months now.
Intermittent false alarms and the dreaded "Safeguard Check" on the display.

I'm pretty sure that I've nailed it down to the alarm siren itself, I thought that the rechargeable battery inside had probably gone knackered and was causing the problem.

However, I've split the siren box and have tested the battery only to find that the voltage at the terminals is a more than healthy 5.3V. (Info on battery states 4.8V)
I know in normal operation the siren should be activated once it is removed from the car and mine is completely silent.

I can only assume that this would mean that there is a fault on the circuit board itself, my first question is, is such a fault with the siren circuit board itself a common problem and secondly, is there any way I can disable the "Safeguard Check" or "Con" the alarm system into thinking that there is a siren connected so as to stop the warning from apprearing on the display every time I turn on the ignition.

I have diagnostics software so if this is an option somewhere within the diagnotics software, I could do this.

I'm quite happy to leave the alarm as it is with the car horn itself being activated as the alarm siren but would ideally want to stop the aforementioned "Safeguard Check" appearing every time I switch on the ignition.

[blue estate]

I had that happening with the alarm going off when it felt like it (normally silly o'clock am!?).. turned out to be sensors built into the rear side windows at fault.. changed under warranty at the time

[John Bishop]

As above had same problem with mine and it was the rear window sensors. There is a how2 on here using a paperclip to fix it. Do a check safeguard search and you should find it

[Saxman]

As above had same problem with mine and it was the rear window sensors. There is a how2 on here using a paperclip to fix it. Do a check safeguard search and you should find it

As OP, I'm pretty certain that its the siren box.

I've checked the window traces for continuity and all other possible sources of the problem and they all appear good.

Also, since I've removed the siren box the alarm has not false alarmed.

(It got to the stage that it was false alarming within Five minutes of being armed)

[vectra ste]

http://www.vectra-c.com/forum/showth...feguard&page=3

this may help

[Saxman]

http://www.vectra-c.com/forum/showth...feguard&page=3

this may help

Have been through all of the checks (And more) that are mentioned in that and numberous other alarm related threads before I made the original post.

So, at the risk of repeating myself, does anyone have any suggestions to the Two questions that I have asked in the original post ?

Your help would be much appreciated.

[vectra ste]

what about an alarm siren from a scrap yard to try out

[Saxman]

what about an alarm siren from a scrap yard to try out

I'm quite happy, in fact I would prefer, to leave the alarm as it is with the alarm siren removed and the car horn itself being activated as the alarm sounder, but would ideally want to stop the aforementioned "Safeguard Check" appearing every time I switch on the ignition.

So, as per my original post, is there any way I can disable the "Safeguard Check" or "Con" the alarm system into thinking that there is a siren connected, so as to stop the warning from apprearing on the display every time I turn on the ignition and whilst still using the car horn as the alarm sounder ?

[Neve'o]

If the sirens are anything like the mk4 astra ones the batteries soldered to the board inside die and cause the alarm to randomly go off (usually at 3 in the morning from my experience!), its advised to change the unit for a new one which was very costly (£75), the other option was to cut open the siren and solder new batteries onto the board (around £20) and this has worked for me before.

[Saxman]

If the sirens are anything like the mk4 astra ones the batteries soldered to the board inside die and cause the alarm to randomly go off (usually at 3 in the morning from my experience!), its advised to change the unit for a new one which was very costly (£75), the other option was to cut open the siren and solder new batteries onto the board (around £20) and this has worked for me before.

Again, as OP. (Does anyone ever actually read the OP ?)

Voltage at battery terminals is 5.3V so is well in excess of its stated nominal voltage of 4.8V