Hi Everyone

I have a 1999 S-Type 4.0 V8 in really nice condition but have a fault with the main alarm going off randomly when the car is locked.

Also when the alarm is cancelled with the fob sometimes the memory seat and steering wheel can be seen moving and dash lights come on after the alarm has been silenced.

I took it to my local Jag specialist who diagnosed it to be the ignition switch. they stripped the ignition barrel and fitted a replacement switch (second hand).

After testing it for a day I brought it back but two days later the same problem occurred at midnight outside my house!

I will contact them about it for re-testing but after spending £520.00 on this I am fast loosing patience with my dear Jag!

Anyone got any ideas it would be much appreciated

 

Welcome to the forum thebutcher44,

I've moved your question from UK & Eire Region to S-Type forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Similar problems on Volvos have been traced to a dying battery in the alarm module. Check that.

 

Thanks for the reply Tony.
I was advised before about battery condition before so I fitted a new one about a month back but will get it checked

 

No, not the car's main battery, the backup battery in the alarm module. They are typically fitted with a lithium battery that is good for 10 or so years. They do weird things when they die.


Not sure about the Jaguar's alarm system but the Volvo has such a module.

 

I have never heard of such a battery in an S Type. I think you will be wasting your time looking for it.

I do however know the ignition switches go bad in the preface lift models. Maybe the second hand switch is faulty as well.

 

Some of the models have a battery (may be a rechargeable) for the alarm. It has caused similar problems and at least a couple of UK guys have disabled it (by taking stuff apart). Whether it is fitted to all years or only some I don't know.

Try looking on S-Type & S-Type R Supercharged V8

 

Hhmmm interesting that the UK may have them. I just do not recall ever reading here on this site about such a battery.


On a side note, I am not a member there on the UK site so I did not search it out. I did see a member there named Kevin inquiring about the chrome door trim a couple of days ago. If you wish, there is a DIY (by you know who here) that would really help the guy out. I will even put up the link for you John to copy and paste.
https://www.jaguarforums.com/forum/s...ics-faq-29860/

 

Out of curiosity, I preformed a search for "lithium battery alarm" oddly enough this is the only thread that popped up discussing such "alarm battery".

 

It's old tech so maybe not lithium? AFAIK it's inside the alarm part and I guess expected to last the life of the car, whatever that was guessed at by jag.

 

I'm sorry that I even brought it up. I just tried to be helpful since Volvos do strange things when the alarm modules get old. Call the dealer.

 

Or better yet here is the IB Brand Volvo site to help with a Jaguars alarm module:


http://volvoforums.com/forum/


BTW there is still no such battery associated with a modern S Type

 

Don't know about the early S-Types but the later ones have them & my XJR also, a "backup alarm sounder module" under the bonnet which in my car has been disabled (using SDD) because the alarm started going off at random times.

It may be that the earlier models don't, or maybe the North American ones don't, or maybe both.

But in regards to the OP's problem, it could also be one of the door, boot or bonnet switches which is failing, happens all the time...

 

The bonnet (hood) one is fairly common and easily checked as it's so accessible.