Horn Failure - 986 Forum - The Community for Porsche Boxster & Cayman Owners

McQuaid · 11-02-2011, 07:44 AM

Hi there

Horn hasnt worked since i got this 99 2.5l, have checked fuse, is fine, when i press steering wheel i can hear a click, i can even hear a click at fuse box

Anyone know what else to check before i go strip front end to get to horn???

healthservices · 11-02-2011, 08:52 AM

doubt the relay is bad but you can check that. Removing the bumper is not hard and you should do it every once in a while to clean out the junk stuck in the radiators. be sure to move the condenser out of the way to clean behind it as well.

Yep, there is a ton of sand in there.

McQuaid · 11-02-2011, 09:03 AM

Wow, looks like that may be worth doing....not a big job to do????

healthservices · 11-02-2011, 09:09 AM

Nope I'm sure I got my bumper off in less than 15 minutes.

97 Boxster · 11-02-2011, 09:54 AM

Directions on how to do this?? Are they listed somewhere? I would like to try this as well and my search function is pulling up an advertisement box. Thanks

healthservices · 11-02-2011, 10:34 AM

go to youtube and enter 'bumper removal boxster' in the search engine

McQuaid · 11-02-2011, 11:32 AM

wow....very easy

Porsche 996 986 bumper removal - YouTube

there's a job for me tomorrow

Just a once off, where is relay box???

McQuaid · 11-03-2011, 06:30 AM

Glad i did that, but, cant see a problem with horns, what should i be looking for down by the horns in terms of a fault?

healthservices · 11-03-2011, 07:28 AM

Get a test light or a VOM and test the leads at the horn (remove from horn) to see if you are getting power and ground at the horn when the horn is press.

I had a shorted horn on mine and it was causing the fuse to blow.

I just removed the leads to that horn as the other horn worked and did not blow fuses

You can also test each horn by momentarily applying power and ground to each horn.

timothy · 11-04-2011, 02:20 PM

The horn also stops working if the ground wire breaks behind the air bag. That's what happened to me.

Burg Boxster · 11-04-2011, 02:33 PM

Quote:

Originally Posted by timothy

The horn also stops working if the ground wire breaks behind the air bag. That's what happened to me.

OP can hear relay clicking which indicates electric components, including frame/bracket behind airbag, are intact inside and working properly. As such, next most typical issue is actual horns are bad. This is a very common failure b/c the way the trumpet is aimed. It's prone to ingest water / salt / road grime etc. causing internal failure. Once bumper skin is removed and leads/horns are tested individually, cause will be readily apparent but my experience says horns themselves are shot.

Typically, b/c there are twin horns, one fails and the owner doesn't readily notice other than horn may not seem as loud as it used to. However, they do take note (pardon the pun) when second fails.

Good luck

McQuaid · 11-08-2011, 02:23 AM

So, had the car up on the ramp this morning to do the oil change, i decided while it was draining to have another quick look at the horn issue, i had a horn lying around workshop and unplugged porsche horn and plugged this in, it immediately sounded, and won't turn off, seems if i put a functioning horn in, its stuck on, can see why old horns blew now

Anyone any ideas??

Burg Boxster · 11-08-2011, 07:17 AM

most common cause is bushings in bracket behind steering wheel airbag are bad allowing contact at all times. However, I thought you stated earlier you could hear relay click on when pushed?

Regardless, test steering wheel bracket by connecting up good horn and either manually pull out on airbag assembly or jamb some cardboard or rags around the edges (stopping frame contact) for it to stop. If it does, issue is common bracket failure. Instead of having to dig in twice on physical horn, replace w/ your temp one (or another one) and just pull horn fuse until you can R&R bracket. For the bracket R&R, either replace entirely ($50-65 IIRC) or repair bushings (< $7 w/ Permatex blue silicone). See this link for R&R links/more details.

If the horn doesn't stop when temporarily pulling on airbag assembly, you may have a short somewhere else but I suspect bracket is cause...

Good luck

McQuaid · 11-08-2011, 07:41 AM

So, since looking earlier, i had a mate help with playing with the airbag end of things while i held a working horn on, turns out if you play with the airbag piece then you can get the horn to turn off etc

So looks like i need those bushings, and 2 new horns by the looks of it?????

McQuaid · 11-08-2011, 07:50 AM

Also, have you got a link to what these bushings look like??

Burg Boxster · 11-08-2011, 08:08 AM

Quote:

Originally Posted by McQuaid

So, since looking earlier, i had a mate help with playing with the airbag end of things while i held a working horn on, turns out if you play with the airbag piece then you can get the horn to turn off etc

So looks like i need those bushings, and 2 new horns by the looks of it?????

Indeed but you can't buy just the bushings, need to either repair for <$7 (very easy just follow DIY instructions in various links) or replace entire bracket for > $50. FWIW, the process will be identical (except add in drying time for silicone bushing repair).

Quote:

Originally Posted by McQuaid

Also, have you got a link to what these bushings look like??

See links in the link I posted above. More pictures than you could ever need...

In the mean time, pull fuse B3 (IIRC but check your fuse guide inside fuse panel door) if you replace horns but haven't yet repaired bushings in bracket.

Good luck