Alarm Malfunction

[mikev]

Hi

Can anyone help.

I have a 97 Corolla fitted with a TVSS IV-S alarm. For the past 4 nights, it has gone off for no apparent reason - just once each night. Otherwsie it is working fine

NB I have checked the door contacts and interior light goes on and off when I open and close the doors

Has anyone had a similar problem? Any Ideas?

Thanks

Mike

[nrgizerbunny]

bonnet sensor? try unplugging it.

[Twincam.GTi]

Have you also had it 'blip' to itself for no reason at all whilst driving along?

Reason I ask is these alarms are renowned for giving trouble because of where siren is mounted - the inside of drivers side inner wing (not in engine bay but behind wheel arch shield towards the front of car). What happens is when it rains water runs down this part of inner wing through a rectangular hole (hole is approx 8cm X 4cm in size below washer bottle) and lands straight onto siren which is mounted below it!

Siren eventually fills up with water inside over time (if car lives outside all the time in rainy Britain then they have been known to go as quick as 3-4 years!) and starts shorting itself out - theres no repair a new siren is required from Toyota ONLY; cost is about £55 for new one.

It's a daft place where they fitted it and about five years ago Toyota dealerships where made aware of it (but they all failed just out of warranty). Some Toyota Mechanics did do modifications though after replacing them - simply glue a neat piece of plastic over hole; it doesn't cause drainage problems as rain water has plenty of other places to run out.

As a side note these alarms have also been known to not 'activate' if car is parked near underground electrical cables. Also if temperature starts to freeze and car has been warm and cooling down then alarm has been known to go off - or vica versa if car is cooling down and it's a hot/muggy night. Again all these could be attributed to dampness/water/moisture that has already got into the siren unit.