I have an Audi A8L 2004.
It seems that the Alarm Horn is not working any more. Any time I push the Panic bottom, the lights flash but there is no Alarm sound.
I let an Indi. mechanic check it and got a quote of $460 incl. parts and labour.
Is there any cheaper way to do it? I think the Alarm itself it so difficult to get to, so is the labour high too. Could I use an Alarm from VW PAssat or simmilar for this?
Thank you,
A.

 

By the way, where is this Alarm Horn located?
Tnx,
A.

 

Under the hood on the passenger side.

See this diagram 2004 AUDI A8 QUATTRO Parts - AudiUSAParts.com

I've heard that there is a diaphragm in the siren/alarm horn that sometimes comes unsoldered over time.

Since it's not working now it might be worth trying to fix.
Otherwise it's about $190 to replace.

 

My alarm horn stopped working. Went to the dealer and a new cost $330 So I ordered one off of Ebay, got installed it same thing not working. So I opened up my horn and found that that batteries were bad leaking all over the place. Cleaned everything up tried to find some new batteries no luck. Found a site (Audi A4/B6 Alarm Siren - Replace NiMH Batteries | Audi-Sport.net) it's from England. It has a way to modify the battery pack. I tried one thing to make sure the horn and circuit board were still good. I plugged the horn back in without any batteries and it works. so some how the bad batteries are screwing thing up.

 

How did you manage to open the alarm horn. Is the unit sealed as I don't see any bolts

 

I have a 99 Audi A4 2.8L and mine sounds like a dying elephant! Any tips for mine?

 

There is a seam where the 2 halves are glued together. I took a chisel and hammer and careful separated the halves. Inside you will find the batteries which are likely dead and leaking

 

Don't know about a dying elephant sound. My alarm horn one day just stopped working.