neanicu

Try turning the wheel a few degrees at a time. Each time you turn,stop and try the horn. If it works at a certain angle but doesn't after you've moved it to a new angle,it's a good indication the clock spring is bad. It sometimes makes contact at a certain angle and then loses it again.

hurricanesteve

I had a horn fail, but there are two (each has a different frequency), and based on comments here, it's not uncommon for one to fail, but I'd lean toward neanicu's diagnosis since both failing at the same time would be odd. Not totally impossible, especially if you didn't notice the "dying goose" sound of just one horn working for a while.

I forgot to take a picture of the original horns when I replaced mine (thread here), but the failed one was totally full of rust. The "good" one was also rusty, just not quite as bad. It's a pain to replace/upgrade the horns, since you have to remove the bumper cover.

They live in a crap place since they are close to the radiator...lots of heat cycling, especially bad in humid conditions. I'm hoping the PIAA horns will be more resistant to the conditions.

Edgy01

Several years ago people were having trouble with their horns, but I believe the horns themselves were the problem.

Iceter

This. Very unlikely for both horns to fail at the same time. Don't know what the problem is, but we can be pretty confident that it's not a simultaneous failure of both horns.

Neanicu's suggestion sounds probable.

Have you tried intentionally setting off your alarm? That's another way to see if the horns are working. They would be receiving a signal from somewhere other than the horn button that way.

neanicu

I do agree that Porsche uses some of the crappiest horns in the industry,so anything's possible...

slicky rick

Porsche is about performance everything else is crappy..eg bose sound, horn, key, headlight assy, etc.. But the performance of the car just makes you forgive these things.

Wayne Smith

Too true!

Meanwhile, I agree that the first thing to look for is not multiple failures, but a single one, almost always. However, I would add one thing in this car ... I don't think I've used my horn more than twice in the last 20 years. Years of motorcycle riding taught me to get out of the way first and foremost. The horn does little good after the fact.

So if you are like me, your first horn could have failed some years ago and your second horn failed sometime after that.

Or, if you are like others, you may not have been listening for two horns so you didn't know one was already dead.

Just saying.

So short of using jumper wires to make temporary connections for testing, the alarm idea is brilliant.

RollingArt

There is a third horn that just does the alarm that lives in the frunk near the battery.

jhbrennan

Maybe previous owner installed an aftermarket alarm and added an extra horn/siren. I've never seen this 3rd horn near the battery.

Found it - didn't know car had 3 horns.

GSIRM3

True. I've had three 997 cars and replaced a horn on each of them. But as others have said, they have two horns and the likelihood of both failing at the same time is slim. For me, it was just one of the two horns that failed on each of my cars.

Wayne Smith

I just checked on my 2010 4S. I've got one horn that works well, I'm not sure about the second horn (I decided to not further upset the pups), and a third horn under the plastic up near the windshield washer reservoir for the alarm.

Good call on noting the independent alarm horn! So much for using the alarm to check.

I'm siding with the common cause camp as opposed to the multiple failure (both horns are failed) camp. That simply makes the most sense.

Hella-Buggin'

OK, I unlocked the car this morning and started it up, pressed the horn button and it let out an asthmatic single beep and then nothing. I slowly turned the wheel and pressed the horn various times to no avail.

CBejbl

Just spent the day in the 991 and noticed my horn doesn't work either. Never seen this before?

Hella-Buggin'

OK, I disconnected the battery for about 20 minutes and then started it up. Still no horn. I did set off the alarm and it went off but it sounded pretty feeble. I emailed my service guy at the dealer and he said that its probably not the clock spring and they often see both horns fail together because one dies and it puts more draw on the other which is usually compromised the same as the failed one. I'll probably bring it in next week if I get a chance.

Hella-Buggin'

OK, so after sitting overnight after disconnecting the battery I now have a horn. I guess that rules out the horns and the clock spring. My suspicion is that when the airbag code was cleared after two months of having the track seat in that it through the ECU got confused. I had an initial PASM & PSM warning but they cleared after awhile. So, while everything cleared up, I got a brake pad sensor error. I have all of my sensors zip tied out of the way but I suspect that when I cranked the wheel all the way to each side one of the connectors made connection with something and caused the code. I'll see how it behaves and if nothing else develops I'll pull the sensors and inspect for damage and re-install.