Hi All,
     omega 2.5 cdx alarm started going off today car running or not! tried turning the interior sensors off in case of insect flying around..no luck..the battery is fully charged any ideas guys?

Cheers Gord. :-/

First place to look is the bonnet sensor, these can give problems on an Omega.

Is it the horn or the power sounder?

If Power Sounder, it could be that the internal rechargeable battery is dead - this can cause the alarm to go off for no reason. Did you hear the omnious 'four beeps' from the engine area? Other than that the most likley cause is a sensor, probably the under-bonnet one, as AA said.

where is the power sounder as my 96 2l has the most discrete alarm ever it just flashes the indicators so methinks there is a wire astray

It's either at the front under the wing behind the inner mud guard or under the scattle board at the base of the windscreen on the opposite side of the Pollen filter - depending on your model etc.

Markjay wrote on 02. Aug 2006 at 09:12:

If Power Sounder, it could be that the internal rechargeable battery is dead - this can cause the alarm to go off for no reason. Did you hear the omnious 'four beeps' from the engine area? Other than that the most likley cause is a sensor, probably the under-bonnet one, as AA said.

It's the power sounder..and I have heard no beeps (yet)...what is the usual falt with the under bonnet sensor?

Cheers Gord.

If its underbonnet sensor (attached to PAS bottle), that normally sounds the horn (you can test which sounder by opening bonnet, press and hold down that switch, arm the car, wait 45s, then release switch - it will be very loud though!)

The power sounder one is normally a problem with the power sounder itself (eg batteries) or the wiring to it...

It gets knocked about when so-called mechanics work on the engine bay, and as result the sensor may be too low and think that the bonnet is open while it isn't...

But this should only get the alarm going while the car is alarmed, i.e. after locking it, if you get the sounder going while the vehicle is not locked then it is not likely to be the sensor at fault - the power sounder battery is more like it.

Markjay wrote on 02. Aug 2006 at 14:27:

It's either at the front under the wing behind the inner mud guard or under the scattle board at the base of the windscreen on the opposite side of the Pollen filter - depending on your model etc.

many thanks sir much obliged

Hi one thing my son noticed is that when the alarm went off the indicators did not flash!! they normaly do..not had time to look at it yet as it's peeing down here.... :'(

Gord.

I have problems with mine going off when the sun gets on it for a while!!

Seems worse if the sun keeps going in then back out again. I thought at first that it might be the ultrasonics so removed them to no effect. Have resorted to disconecting the battery when its going to be stood for a few days.

PhilCavSRi130 wrote on 04. Aug 2006 at 00:55:

I have problems with mine going off when the sun gets on it for a while!! Seems worse if the sun keeps going in then back out again. I thought at first that it might be the ultrasonics so removed them to no effect. Have resorted to disconecting the battery when its going to be stood for a few days.

Mine only started going off after I left my rear blind up??? since I lowered the blind it's been ok since..could be coincedence?? :-/

PhilCavSRi130 wrote on 04. Aug 2006 at 00:55:

I have problems with mine going off when the sun gets on it for a while!! Seems worse if the sun keeps going in then back out again. I thought at first that it might be the ultrasonics so removed them to no effect. Have resorted to disconecting the battery when its going to be stood for a few days.

I would almost certainly suggest it is your bonnet sensor that is causing the problem, especially as it happens when the sun gets on it. Common problem.

PhilCavSRi130 wrote on 04. Aug 2006 at 00:55:

I have problems with mine going off when the sun gets on it for a while!! Seems worse if the sun keeps going in then back out again. I thought at first that it might be the ultrasonics so removed them to no effect. Have resorted to disconecting the battery when its going to be stood for a few days.

Disconnect the plug from the switch to prove it. Switch is normally closed - shutting bonnet should open it, so that when Johnny Toe-rag opens the bonnet it closes, switches to ground/earth & triggers the alarm. If the switch is disconnected it won't be able to switch to ground/earth. The switch bracket probably just needs straightening so that the switch is vertical.

....or glue a rubber grommet on top of it....

Well at least I know it's not the sun causing my alarm to kick off....it's just gone off now (4am) so out of bed into the rain to disconnect the battery... >:( :-[

Gord.
Ps now going back to bed peed off and wet..Grrrrr >:( if I can turn our other alarm off..our Alsation!!  ;)

The bottle is held in place with a clamp like belt.  If you undo the bolt which tightens the belt, you can raise the bottle a few mm and hence the switch.  

It was enough to cure mine.  

You can as Mark said, glue an extra pad under the bonnet where the switch touches.  

Thanks for that i will give it a try and let you know the outcome  ;D

(sorry for delayed responce been in Devon for a week!!)