Yesterday the alarm went off randomly, leaving the hazards flashing after the siren stopped. There was no one near the car. I turned the ignition on but there was no 'Service theft alarm' message as I had been anticipating. I re-locked the car and it appeared to behave for the rest of the day / night.
Since the car is ten years old, is this the usual failure of the batteries in the alarm unit, causing random alarms? Or does the absence of the 'Service theft alarm' message suggest it might have just been a glitch?
ISTR that, if the alarm unit is going off randomly and needs replacing / disconnecting etc, two short-term solutions are [1] locking the doors manually, which secures the car but doesn't activate the alarm, and [2] pulling fuse 14, which the car will run without but which also kills the AC.
But any reflections welcome...
My Aero is also ten years old. It had the SERVICE THEFT ALARM on it when I bought it, three years ago. I had it TECH II'd off and used the horn as the alarm sounder.
Fast forward to earlier this year, my alarm would siren started to go off. No indicators flashing, and wouldn't go off. Car would lock/unlock OK, I also had the appealing "sight" of the siren going off whilst the keys were in the ignition and car was running....
No further SERVICE THEFT ALARM appeared even when the siren was wailing away at two o'clock in the morning.
Took the siren box off (with the car battery disconnected) opened it up and pulled the siren connector. Sealed up the box and refitted it, connecting it back up to the car and put the battery back on. As far as the car "knows" it's never been off the car and is still, probably, making the now mute siren go off.
Not to bad to get at, up in the front n/s wheel-arch, not too sure what affect just unplugging it would have, I'll put a new, read s/h one in at some point. Seems an easier option than soldering in new batteries and caps.