Thom1

How do I get to the horn workings? Do I just grab the horn cover in the steering wheel top and bottom and pull?

Are there adjustments to shorting springs and/or mechanism?

When I turn the steering wheel, it sounds the horn off and on several times per turn. When I lightly touch the horn cover it blows. Prior to this, it blew a fuse. That also caused false alarms while the blown fuse was in place.

Thanks in advance for any ideas.
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Tool Pants

You are going to have to remove the air bag and see what is going on with the horn contacts. Disconnect battery, remove air bag with a #30 long torx bit or torx screwdriver, and disconnect the yellow connector in the back of the air bag. Do not let the air bag hang by the connector or you will break 2 plastic pins on the air bag spiral spring.

You will then see a spring loaded metal plate. When you press on the air bag it presses on the plate and the springs are compressed. There are 4 contacts on the plate and when one of those four contacts touch the matching contacts on the wheel the horn blows. You can see one of the wheel contacts in my picture.

4 bolts hold the spring loaded plate and a spring is under each bolt. You can see one of the bolts in my picture. I think the bolts are insulated from the plate by the plastic/rubber bushings under each bolt head and if these bushings get worn the contacts touch each other and the horn goes off when moving the wheel. That is my guess anyway.

If you want to test the horn by pushing on the plate with the air bag disconnected by hooking up the battery you will set off the air bag light which can only be turned off by a dealer. Jeff

<img src="http://www.986host.com/albums/ToolPants/horn_button.sized.jpg" alt=" - " />

Thom1

Thanks Jeff,

That is an excellent explanation… even down to the air bag warning. I already set that off when I moved the car with the seats removed. So, it shouldn’t cause further harm could it?

Do those 4 bolts adjust the tension? If not, how do I adjust it?

Does the horn cover just pull off with a quick pull?

Is there a good place to buy Boxster parts? For the 928, we have the Big 3 who specialize in 928 parts and advice?

The problem came with the car a couple of months ago. The fuse had been removed. I had the horn “fixed”/springs adjusted sight unseen before I picked up the car. I have had an alarm error since I got the car (horn chirp when alarm is set most of the time.). But, the false alarms only started after the horn shorted out and the fuse blew. When I replaced the fuse, the false alarms ended. Then the unwanted horn blows started. Any thoughts? If I fix the horn can it get rid of the alarm error indicators? Can that be reset by the dealer like the airbag light, or will it go away when I solve the problem?
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Tool Pants

The air bag is bolted to the wheel with 2 torx screws that you remove from behind the wheel. You cannot just pull it off until you losen the 2 screws If the warning light is on then it's on and the air bags system works even when the light is on - but only a dealer can turn it off with the PST2. I have not played around with the 4 bolts as most 4 spoke older Boxster 996 owners I know have have changed the 4 spoke to a 3 spoke. Many cheap 4 spoke wheels on ebay for this reason if you do not want to play with your old wheel, and you cannot buy parts. Same wheel was used on a 993.

Alarm horn chirp is because something is not closed when you arm the car. Most common is the lid for the center console storage, or you can have a bad switch on the lock for the lid. The pair of horns for the wheel are behind the bumper cover, and the alarm horn is next to the battery. So the alarm horn is separate from the wheel horns. With the PST2 they can see on the screen if there are faults in the alarm system.

There is a new Porsche technical board if you need more help. <a href="http://www.renntech.org/index.php?s=2bc6ff59cf46960ffdea96137a681983" target="_blank">RennTech</a>

<img src="http://www.986host.com/albums/ToolPants/tools_airbag.sized.jpg" alt=" - " />

<img src="http://www.986host.com/albums/ToolPants/josh2.sized.jpg" alt=" - " />

Tool Pants

Same problem it sounds like.

<a href="http://forums.pelicanparts.com/showthread.php?s=&threadid=116305" target="_blank">Pelican</a>

Thom1

Thanks Jeff,

I have a new Torx tool that won’t get stuck in the hole. A mechanic also advised about disconnecting the battery. He had seen a mechanic hit by an airbag. Singed his eyebrows, loud bang temporarily impaired hearing, hit in the face, out of work for a week. Evidently, wiggling the live contacts can set it off.

I had to help out my sister with an emergency last night. Will let you know how it goes soon.
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Thom1

Solutions:

I installed slices of hoses in 2 places. The first was behind the horn pressure plate where the 4 bolts attach. The second was 2 long sleeves on the switch ring prongs that go into slots in the steering wheel after the large retaining nut and wheel have been removed.

There were no traditional springs. The 4 holes in the pressure plate had rubber membranes like wheel spokes and spider webs. In the center of each was a metal sleeve through which the bolt goes. The rubber was too weak to hold the pressure plate. I sliced some hose about an eighth inch thick to put behind each rubber membrane, behind the pressure plate. The horn is a little hard to sound now. But can be done easily enough with thumbs or palm. I would use some 1/16th inch rubber washers for a more sophisticated fix.

When I removed the big nut and the steering wheel, the 2 prongs were broken that went into the wheel slots. In the second picture you can see the broken prong end piece placed over the lower broken prong. In the third picture, see how I fixed things with hose sleeves.

See pictures at: <a href="http://photos.yahoo.com/bc/thomhross/vwp?.dir=/My+Photos&.dnm=986+Horn+Cover+Airbag+removed.jpg&.src=ph&.done=http%3a//photos.yahoo.com/bc/thomhross/vwp%3f.dir=/My%2bPhotos%26.dnm=" target="_blank">http://photos.yahoo.com/bc/thomhross/vwp?.dir=/My+Photos&.dnm=986+Horn+Cover+Airbag+removed.jpg&.src=ph&.done=http%3a//photos.yahoo.com/bc/thomhross/vwp%3f.dir=/My%2bPhotos%26.dnm=</a> 986Wheel%2bremoved%2bprongs%2bbroken.jpg%26.src=ph

So far, the alarm does not chirp when I set it. After 21 flashes, I get the perfect one flash (not 2 flash). This leads me to believe that the alarm system also read shorts that were previously in the horn area. The short source may have been due to the closed horn circuit with and without the fuse in place. The short source may have been due to the broken prongs and loose switch. I conclude that the alarm circuitry senses shorts as well as open compartments. If I get more false alarms, I will update this post.

Jeff,

Thanks for the great help. Feel free to use the pictures on any other sites.
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Tool Pants

Like to see people work on Boxstirs, it is just like any other car. The 2 plastic prongs on the air bag spiral sping are just for anti-rattle, nothing else. I have seen many broken ones as people let the air bag hang from the connector and the weight breaks them, of if you do not put the wheel back on so that they go into the square holes they will break. No big deal.

Will look at your pictures, but I have removed about 30 plus steering wheels for the OBC hack or 3 spoke swap. I will see how you fixed the horn 'springs.'

<img src="http://www.986host.com/albums/ToolPants/03_trip15.sized.jpg" alt=" - " />

<img src="http://www.986host.com/albums/ToolPants/03_trip21_001.sized.jpg" alt=" - " />

Thom1

Guess what happened. The darned alarm sounded again. I again get the chirp and double flash LED. It looks like the horn short and false alarms were coincidental.

The good news is the horn fix works great.

I cannot find an alarm relay on PET5. Is there something other than the alarm brain drawing on PET? Does anyone know which relay(s)could be defective? Is there an identical relay that I can switch to test it? With the 928, replacing relays often solves problems.

The false alarms typically sounded within 5 minutes when the horn fuse was removed. Today the false alarm sounded at about 9 and 15 hours. This scenario played out at times before the horn started shorting.

Is there a way to troubleshoot false alarms without taking it to the dealers diagnostic machine? Has anyone solved false alarm problems?

Maybe I should start a false alarm thread.
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