2002 996T - Funny horn behaviour?!

Hoping some of you kind people may be able to help with a really weird issue I had today with the horn sounding on my 2002 996 Turbo Tip Coupe. As background, the front passenger side sunroof drain is leaking into the passenger footwell - I haven't been able to find the exact point the water enters the car yet, but I can see water drip down from the underneath of the dashboard, in the front outside (nearest kerb) of the passenger footwell when I pour water into the front passenger side sunroof drain. It's rained very heavily where we are the last couple of days and I've been tied up with work so haven't been able to attend to the car. Opened her up to take a look this morning and the carpet is very wet, despite me having a rolled up towel in there to try to absorb most of the water before it goes anywhere. Anyway, this afternoon my wife walked past the passenger door and heard what sounds like a relay clicking rapidly. I opened the door (it was unlocked) and the alarm went off. I then put the key in the ignition and turned it to pre-ignition, then to ignition and the alarm was still going, even though the engine was running perfectly. So, I took the key out of the ignition, unlocked and locked the doors via the remote, still alarm going off. Put the key back in the ignition, turned it to pre-ignition and ignition and the car started, but still with the alarm blaring. I then put the key in the driver's door lock and locked and opened the car and held the key in open and the car dropped the windows. Still alarm going. So, as a last resort, I popped the bonnet and disconnected the ground at the battery, at which point the alarm stopped and the horn started! Went back to the car, put the key in the ignition and turned to pre-ignition and the horn stopped. After a few hours, I reconnected the ground at the battery and all seemed fine. Car was perfectly happy. A little while later, the horn started to "beep" very briefly every couple of minutes. Then the gap got shorter over the span of a few minutes, then it stayed on. So, key in the ignition and then disconnected the ground again. I can't risk trying it again tonight as the neighbours have already had enough from us with this plus building work! :nooo: Can anyone suggest why the horn is behaving like this? Could it be shorted by water somewhere? It doesn't seem to be an alarm issue anymore - as the engine will start no problem and the key buttons work as intended (unlock, lock, drop windows, etc). Grateful for any tips that can be offered! :thumb:

I should add - the horn always beeps a few seconds after locking the car. I understand this can be a flooded tilt sensor or a failure of the backup battery in the alarm siren itself? Not sure if it's relevant, but thought I'd mention it!

There are several threads posted up by forum members experiencing similar issues. Make sure all things that can be closed are in fact closed prior to locking, eg armrest cubby hole, glove box (if fitted) etc. Other threads are available via searching the site. http://www.911uk.com/viewtopic.php?t=56944&postdays=0&postorder=asc&start=20

I sometimes wonder whether the moderators on this thread actually want members to post on here. Passively agressively telling members to wade through 10 yera old posts is not a particularly welcoming attitude. You realise that with no posts, this forum dies?

The last line of your initial post suggested that you were seeking help, unless I'm mistaken I have offered you two possible remedies, or at least avenues in which to find it.

You offered a solution to a problem that I'm not trying to fix - chirping horn after locking. I know there are various avenues to go through to check that. The link you posted was also about the non-issue of a chirp after locking. The key problem and the one I wrote a huge post describing, is the weird horn behaviour. Advising a 7 year member to "use the search engine" could easily be taken as a passive aggressive telling off, especially coming from a mod. It's not the first time I've had it in response to a request for help either.

What a bizarre comment to make to someone who has taken the trouble to respond to your request for help! As Forum Moderators we know the site better than most and it's therefore fairly standard practice to point people to where there may be an answer to their queries, especially if it's a common question. Recipients are normally grateful as it gives them something to go on until a personal reply is posted by others. Occasionally we get the wrong end of the stick - as pzero seems to have done in this instance - but your reaction was, quite frankly, disrespectful if not plain rude. I note that no other forum members have replied to date and wonder if this may be because your thread title doesn't really advertise the fact that you need help. Hopefully me posting this will serve an added purpose in bumping it up the board for you. Anyway, moving on ......... The Alarm Control Unit in your car is under the passenger seat and if this gets damp it will undoubtedly lead to the issues that you have experienced. I don't know whether deactivating the alarm leads to other issues with the horn but I suspect that it might.

Thanks for the helpful advice. It doesn't seem to be an alarm issue anymore - that was kind of my point. The engine starts perfectly well with no alarm now. The horn by the battery for the battery disconnect alarm now goes off randomly and stays on. I've disconnected that horn for the moment and all is well.

I've pm'd deMort linking your thread. If he can't help nobody can.

You have a water leak n/s/f .. that sounds very much like the sunroof drain tube has split in the dash area .. seen a couple of posts recently about that on here but as of yet i've not come across it in person . The fix is a new tube run from the sunroof down to the wheel arch ... not an easy job . Ok then .. your issue .. under the passenger seat is the alarm control unit .. right next to your very wet carpets and water leak . I think i'll go with ... 95% chance this control unit has got wet .. that's based on your fault description .. the car won't beep rapidly every few mins without it being a control unit fault .. they just don't do this .. Water and a control unit and all bets are off as to what faults will happen .. seen very strange faults over the years with water . I would say 100% this is the issue but as i cant see the car and i never say something is a problem or is fixed until i can prove it then 95% it is .. trust me .. you wont get higher from me ! car beeps on locking .. a separate issue and it indicates the alarm system can see something open when it should be closed on locking the car .. center console cubby lid is a favourite but it can be glove box , siren .. door lock etc etc . In short .. remove the passenger seat .. disconnect the battery .. ignition on then remove the neg lead .. have a good look at the alarm control unit .. I expect there will be corrosion inside on the circuit board and i expect it will need replacing but you never know .. you might be lucky .. car starts so that's good .. whether all functions will work has yet to be seen though . After that a new sunroof drain tube i expect .. I think that's covered it all

Thank you very much for the detailed response! PM your paypal or the address of a favourite charity and I'll buy you a drink/donate on your behalf. :thumb: PS: what happens if I simply block the offending drain hole with a bit of silicone sealant? Hopefully the other 3 sunroof drain holes will just pick up the slack and get rid of the water? :?

With all due respect, half arsed repairs like this cause wider problems, get it fixed properly and have a car that you know is right in every conceivable way. When it comes to selling, you can say with hand on heart, your car is well maintained and has wanted for nothing and be proud about it. I look forward to your for sale ad with "Fixed leaking sunroof drain with a blob of sealent"

Outstanding! :worship: :worship: :worship:

+1 DeMort, you are a great asset to this forum :worship:

Honestly, the car is about as far from a garage queen as you can get. It's also going to very far from standard and optimised for fast road / track (as far as you can take a Tip, anyway!). The idea of spending several days in a garage and £hundreds to fix a sunroof drain leak that could be solved in 5 minutes with a blob of sealant is well in line with my plans for the car. Don't worry though, I'll be honest about its history when it comes time to sell, but I'm hoping that may well be decades from now (unless someone offers me an unmissable deal on a Ferrari!).