97urS6

My alarm horn stopped working about a month or so ago. But the door all lock / unlock with and without the keyless system. The lights flash to indicate the system is armed... basically everything seems to work normally except no beep from the horn.

I picked up a used horn unit... replaced it which was easy enough above the firewall cowling on the passenger side. But it didn't solve the problem, still no beep?

Do that means one of two things: either the replacement horn doesn't work or there is some other problem?

Is there any good way to test if the horn works? I tried to apply 12v to every combination of the 3 connector pins in the horn... but no beeps?

Then I was wondering if I can test if signal is actually getting to the horn on the wire? Any ideas on how to test that?

mishar

You can't test it because it is triggered by an electronic signal rather than simple power to the certain wire. Actually it might be that you burned it by applying voltage. In there is a battery that stop working over time. Replacing it with used one can help for some time, or it can be already dead. Only way to fix the problem is to buy a new one.

Besides that chirp can be turned on/off by VCDS. You may try if alarm will trigger the horn.

the_duke

Mishar gives good advice. Press the panic button and see if it makes noise. If it does then you have another issue. VCDS will tell you what is keeping the alarm from arming if that turns out to be the problem.

97urS6

I tested the "panic" button... it makes the lights to flash on and off... as expected. But the horn does not bleep. So I'm guessing the used horn doesn't work. Fortunately, the parts provider (Wolf Auto) does provide a warranty and he will replace or refund.

I only tested the horn with 12v on the original unit, not the replacement unit.

jlbell

Mine died just the other day. It appears the issue is the batteries or water leaked in and caused the board to corrode and create an open circuit. I also had two error codes stored in the system as well. On some alarms the batteries will just die eventually and they just require them to be changed, but mine in my opinion is beyond fixing to due the circuit board corrosion.

97urS6

Wolf Auto is sending a replacement horn unit, hopefully that one will be the ticket.

Shark_V8

You can certainly test it. Lock the car with the hood up. Then unplug the horn, but holy crap wear ear plugs

I think that was my sequence (SOE)

97urS6

Are you sure that's the sequence? If the horn gets unplugged how will it make a sound?

Turbo Tony

It has a battery backup (which is what causes most of the issues)

Shark_V8

Correct, it's the internal battery-powered anti-tampering feature of the alarm system. Which if you were in the "please steal my A8 so I get the insurance claim$$, & rid myself of these codes and get something else" camp, you'd wish was never there.