Ticking noise from inside boot
 

Just this afternoon I noticed quite a loud ticking noise coming form inside the boot, around the alarm horn/CD changer area. It’s ticking regularly, with the ignition off, at around once per second, and has been doing so for some hours now. (I don’t use the CD changer, but I do have phone prep, which I think is in that area too).

Hopefully nothing serious as we’re just heading off to Scotland!

Anyone got any ideas? :Confused:

Does your alarm siren still work Jim? If not, might just be the old leaky siren battery problem causing the siren circuit to emit the ticking noise.

I’m not sure if it’s still working. Brian gave me one a year or so ago and it was OK when I fitted it. But I think I’ll take the damn thing out as this is the third that I’ve fitted. Unless anyone has found a lasting solution?

My lasting solution was to take it out and throw it away ;)

Before I copy Brian’s solution, does anyone know if a compatible new alarm horn is available? Preferably one that you can hear clearly!

Not aware of a compatible horn unfortunately, and you're already quite aware of the (continued) issues of replacing them. I replaced mine back in October 2013 with one I had scavenged from an '05 A4, and it still works, but you have to the hearing of a dog to notice it. It seems to lose volume as time goes by, that's assuming the batteries don't get to it first.

If I lock the car standing by the drivers door, I can't even hear the confirmation beep. As for the alarm itself, I just tested it (again from the drivers door) and it is pathetic.

This is the guts of the faulty alarm horn. probably past saving!

Mine is a replacement that I bought some years ago from our sponsors.
It's still fairly "chirpy" but VCDS throws up a "low internal voltage" error and has for ages.
So, some day I'll probably open it up and replace the batteries before it gets that bad!

It's predecessor was the older shape and a real corroded mess inside, though when I cleaned it and replaced the batteries it did actually work.
But it was never great so I decided to fit one of the newer style ones and hope! (The newer shape also has a different mounting bolt so I had to get slightly creative to fix it.)

So, Jim, clean it up and fit new batteries, you never know! +++

You can't go for anything too new though if you do replace them; they look the same (and have very similar part numbers) but there are subtle difference in the wiring and/or communications protocols and despite investigating for ages I never got anywhere.

That must be a newer version from the original fitment, as the PCB is smaller than mine when I pulled it apart, although mine was well past it anyway, as the three connector pins on the PCB were also corroded, as were the pins in the loom connector block.

That might actually be saveable. As long as the PCB tracks are all intact and it hasn't corroded anything else, it may just need a clean-up and a new battery

My original unit was much worse than that; the leaked battery chemicals had eaten part of the adjacent transformer/choke and corroded away numerous PCB tracks.