Alarm keeps going off regularly -quick fix to silence it needed

[HPsauce]

Originally Posted by HPsauce

I might look at swapping the sounders over to see if that's the problem on the 25yo original.

Well all that I've proved is that I have two faulty alarm sirens with different electrical problems!
I've tried both units, with and without batteries and with both speakers in turn.

The original talks happily to the car and enjoys new batteries when fitted, but won't drive either speaker (they have the same connection).
The later one loses communication with the car triggering the alarm. It works with either speaker. Without batteries it still sounds but throws battery voltage errors of course.

So if anyone coming to the meet in June happens to have an old spare alarm siren kicking around I'll happily relieve you of it and see what I find inside.
(Original 8L0 951 605 or later 8L0 951 605A)