random alarm siren triggers?

[roxburgh52]

Hi I just (3 weeks) got my XJ8 exec 3.2 done 500 miles and love it i used to have a 3.6 XJ40 soverign 10 years ago so new to this model.
Problem Alarm started going off for no apparent reason after 90 mile journey 20 mins latter off it went unlocked opened door locked 40 mins. Left overnight on drive ok then in morning having checked the net noticed bonnet open not functioning touched switch and it came apart ordered a new one left car unlocked under new club cover 2 AM offit goes again open close doors ok till 8 PM connect battery charger leave coverd ok 24 hrs have battery checked all ok then with car uncovered but on charge it went again, fitted new switch from Barretts Ashford drove home fine locked car 20 mins later off it goes.now on charge undercover locked and unable to attend my Xmas Dinner in it (Dont want to be owner of annoying car in car park).
Any Suggestions (other than a can of petrol !)
Dave

[robv12]

I have a dim and distant memory of 308 alarm sounders filling with water, causing corrosion and short circuits, worth having a look at the unit, from memory located behind the left hand headlight unit

[robv12]

Roxburgh52 are you in Roxburghshire by any chance, if so you are not far from me

[ptjs1]

Dave,

Just a thought - disarm the perimetric sensor inside the car when alarming it just to eliminate that possibility .

Paul

[roxburgh52]

Hi robv12 thanks for the info and unfortunately i'm in Kent.
thanks also to Paul but have tried that by both using key and central locking button!
If no joy with water in sounder it looks like a trip to main dealer for Diagnostic its driving us mad and have resorted to leaving spare key with neighbour when going out
Thanks again Dave
PS 35000 miles in the old sovreign and only a viscous fan oh and plenty of metric tyres in 2yrs

[Orkney]

Is it possible to separately disarm the peri metric sensor and if so, how is it done? Perhaps cover with gaffer tape to test?
Ian

[Zennan101]

Hi,

I sometimes leave my dog in the car. (I know, I know... but it's a car!) When I do this I lock the car with the key this sets the alarm but doesn't arm the internal motion sensor......

Rod

[Orkney]

So simple, but I never knew that, many thanks. It probably says it in one of the multitude of hand books but us men don't bother reading such things (so Christine tells me)
Ian

[Zennan101]

Hi Ian,

Don't feel too bad about it. I didn't find this nugget of information in a manual but from the local main dealer when I went in to ask if the internal motion sensor could be programmed not to activate....

As you say so simple!

Rod

[roxburgh52]

UPDATE
I took the car back last Friday and they checked it out and found errors? in the internal sensors and that seemed to cure it! that is until I got home they left them disconnected just to check but then 3 times in an hour including just locking with KEY. Saturday AM I locked it and washed it 2 hours all ok. so turned it round (slight incline on drive) 4 hours ok unlocked and relocked 20 mins off we go again so another night unlocked. Sunday late morning i locked it and guess what off it went
The garaged booked it in for Wed am with loan car till fixed, so I am off again lunch time to collect it. They took all door cards off and checked all sensors computer does not recall the faults? But they have found a faulty boot lock sensor and changed it so fingers crossed.
Thanks for all the advice/suggestions will let you know if all is ok after the weekend its suh a shame as it ruining an otherwise purrfect car and its a 180 mile round trip which is more enjoyable in the JAG rather than the Galaxy diesel auto

[roxburgh52]

Silence is golden! well amoungst other things the boot switch was faulty/loose? and with adjusting the sensitivity I m back to normal and the Jag is too also the neighbours are delighted.
Thanks to Trevor @ Hurst Park Auto's and Lewis & Baz @ Walton Road Garage for persevering and solving the issue for me.
Also thanks to the rest of you for advice and support and a great Club especially the Magazine!
Regards to all for the new (Silent fingers still crossed) New Year hope to get to some events too.