Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: perfferle on 24 February 2008, 21:33:53

Title: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: perfferle on 24 February 2008, 21:33:53

Hi,
Has anyone ever heard about the alarm being triggered by high ambient temperatures / sunshine. This is a really annoying problem that I have ONLY during summer months at about 11.30am EVERY DAY with the car locked/armed. Please let me know your thoughts.
Thanks,
P.

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: VXL V6 on 24 February 2008, 21:34:42

Bonnet switch?

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: perfferle on 24 February 2008, 21:38:34

Dear VXL,
Hmmmmm. Good idea. I will check switch resistance.
Thanks and kind regards,
P.

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: VXL V6 on 24 February 2008, 21:48:45

Easiest test is to unplug it. The usual reason for the fault is because mechanics part swappers bend the mounting bracket when working in the engine bay.

As the underbonnet temperature changes the bonnet expands and contracts, if the switch doesn't make the correct contact with the bonnet the alarm is triggered.

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: Andy B on 24 February 2008, 23:13:49

Quote

Dear VXL,
Hmmmmm. Good idea. I will check switch resistance.
Thanks and kind regards,
P.

The switch will be fine, normally open & the bonnet closes the contacts as you shut it. As VXL V6 says the bracket wil be bent.

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: GrayUK on 25 February 2008, 15:22:43

Normally open??
The tailgate switch on the estate is normally closed, the tailgate, when shut, opens the switch.
Are they different? If so why?

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: jules on 25 February 2008, 16:34:02

Quote

Hi,
Has anyone ever heard about the alarm being triggered by high ambient temperatures / sunshine. This is a really annoying problem that I have ONLY during summer months at about 11.30am EVERY DAY with the car locked/armed. Please let me know your thoughts.
Thanks,
P.

Is there water in your passenger footwell ?

High temps causing it to evaporate and activate the ultrasonics ?

 ::)

Just a random thought

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: Andy B on 25 February 2008, 16:44:41

Quote

Normally open??  ......

Yes cos you test by unplugging it.
No idea about the tail gate & I've never had need to look at the boot switch on my saloon.

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: GrayUK on 25 February 2008, 19:32:11

I would have said it was normally closed, then when you shut the bonnet it opens the switch.
When you remove it for testing you are in effect opening the switch, as would happen if the bonnet were closed.
I will test mine and see , but it makes sense that they would all be the same, could be wrong though. :-[

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: mantahatch on 25 February 2008, 19:39:44

I think what is meant by "normally open" is the contacts in the switch are open when the bonnet is closed, I believe it will be the same for the boot switch and indeed the similar idea of the door courtesy light switches are normally open when the doors are closed.

I hope that makes sense.

Mike

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: GrayUK on 25 February 2008, 19:47:44

OK understood.
Normal ident on switches is the state it is in when not activated i.e. out of the car in your hand or with the bonnet open it would be normally closed.

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: mantahatch on 25 February 2008, 19:56:57

Hi
Yes to complete the circuit on the bonnet switch you open the bonnet the switch comes up and electrical contact is made.
When the bonnet is shut the switch is pressed down and the electrical circuit is broken.

Hope I have explained this ok.

Mike

Title: Re: Alarm Fault on 2.5 1999 Saloon - One for the books
Post by: GrayUK on 25 February 2008, 20:02:24

Yes, no problem, it is a normally closed switch then, the same as the boot/tailgate switch.