Replacing a battery backup siren, 25 year old alarm gurus?

[Skylark NW]

I have a Serpi Star cat 1 alarm system which was fitted almost 25 years ago. The car spends most of its life in a garage and hibernates over winter. Unsurprisingly, the siren battery backup is dead. The rest of the alarm works just fine.

I've tried to split the alarm with the intention to replace its internal battery but not as yet succeeded. I've tried a hot air gun, a Stanley knife, a Dremel fine disc and a junior hacksaw. It looks as though the two halves were sealed during assembly. I don't want to break it, risk of immobilising the car (?) so I've re-installed it, see picture.

Hence my question is to ask if there is a suitable replacement available? The siren has 4 wires, said to be:- Positive. Negative. Negative Control and Coded Communication.

Thanks in advance for any suggestions.

 

[Old Salt]

If its a replacement for the Spitfire have you tried contacting the TSSC? You could always fit a hidden switch to prevent it being started. If its for insurance purposes it may well need to be fitted “professionally” now.

I have seen systems on fleabay for about £175 but they will probably need to be wired differently to your existing system. It may be worth asking on the TSSC or Club Triumph forums as someone may have had the same problem.

 

[Skylark NW]

Many thanks @Old Salt for taking the time to reply. The siren is fitted to an old Ford, not the Spitfire. That said, I've already posted the same question on the TSSC forum. Normally, there's a wealth of knowledge and experience freely shared on that platform but, regretfully, a 25 year old alarm is probably a bit too new for them

The Gemel Serpi Star was widely used in the 1990s. The alarm works perfectly, just the issue with the battery backup. The easiest solution by far is to replace it but it's no longer available. I'm hoping that some other siren can be used in its place, using the 4 wire connections described in my OP.

 

[Harry Bloomfield]

There is what might be a bypass plug available here - https://abacusalarms.co.uk/alarmshop/accessories-spare-parts/gemel-serpi-star-parts

 

[Skylark NW]

Thanks, @Harry Bloomfield but mine is a GR480. My worst case scenario will be to remove the alarm and replace it. I'll get this done by a professional installer. I don't want to do this until I've completely exhausted the search for a compatible, replacement siren.