Horn Problem

[gnat]

Thanks for this thread. Her 996 started randomly beeping at me for no apparent reason on my commute home the other day. Found this thread via Rennlist, ordered a new bracket, and installed it today. Hopefully the beeping will be fixed now.

Thanks to those that figured it out so long ago and posted about it.

[steve20186]

My bushings were intact but weak enough to cause the unintended horn blow.  I ended up using some fuel injector o-rings.  They fit sungly around the isolated center bushing and seem to add just enough firmness.   I only added them to the side that has the contact points.  Seems to work well.  I had some leftover from a recent FI replacement on our minivan, but you can buy a kit of 12 for under $8 local - it's a Standard Brand part.  Or from here: http://www.rockauto.com/catalog/moreinfo.php?pk=47178&cc=1432097.

 

Oh my...I just admitted to using minivan parts on a Porsche :eek:

[bkbville]

This forum is terrific!

 

I picked up a '98 a couple of months ago, and the horn did not work. I could hear the relay when I pushed the horn button - fuse was good.

 

I replaced the horns and (as you might suspect) the horn went off the first time I hit the brakes!

 

Good thing I had picked up the #31 o-rings at home depot already (after reading this thread)

 

I disconnected the battery but never bothered to disconnect the air-bag - had the required access to insert the o-rings.

 

Horn works perfect now.

[boxster_nut]

I had some extra time over the weekend so I took some pictures of the fix for the horn covered in the earlier post. The o-rings measured .300 x .580 and .140 thick. The nylon washer measured .375 x .875 and .031 thick. The image below shows the hole after the center is remove, the components partially disassembled, the components together, and the components assembled to the frame.

I know this is a old thread but wanted to update with my experience.  I didn't have to go through all the work here.  The bushings on my 97 while deteriated, wern't completely gone.  All I did was get #31 o-rings and put them over the center sleeve on *each*  side of the bushing. I did not fix them in place with silicon...didn't see the need as they are fairly snug on the sleeve and when assembled, are sandwiched between the large head screw, the horn frame, and the contact block in the steering wheel.  One could seat them in silicon but I do not see the need to spend extra time while the silicon dries.

 

A fourty minute job and back together and good as new.  One can get the #31 o-rings at Home Depot or Lowes, mfg by Danco, ten in a pack for $2.50.

 

Hope this helps someone with their repair.

J

[996smn]

I have a 2000 996 Cabriolet and was experiencing horn honking during braking or hard turns.  Read the forum and followed the suggestions.  Problem solved. I found o rings in the plumbing section of Home Depot.  Used #231 O Rings 9/16" O.D. X 5/16" I.D. X 1/8" thick.  Thanks for all the help and suggestions.

[aeichmiller]

I have a 99 996 with the 4 spoke wheel. I was having the issue of the horn going off under braking, and then not working at all. I just replaced the airbag frame and still no horn. I checked the B3 fuse and noticed it was blown. Tried replacing with new fuses and they blow immediately.

 

Is this the relay that is bad? Is it the horns themselves?

Edited March 21, 2018 by aeichmiller

[Loren]

3 hours ago, aeichmiller said:

I have a 99 996 with the 4 spoke wheel. I was having the issue of the horn going off under braking, and then not working at all. I just replaced the airbag frame and still no horn. I checked the B3 fuse and noticed it was blown. Tried replacing with new fuses and they blow immediately.

 

Is this the relay that is bad? Is it the horns themselves?

 

Likely one of the horns. They are perhaps the cheapest horns Porsche could have used.

[aeichmiller]

On 3/21/2018 at 5:59 PM, aeichmiller said:

I have a 99 996 with the 4 spoke wheel. I was having the issue of the horn going off under braking, and then not working at all. I just replaced the airbag frame and still no horn. I checked the B3 fuse and noticed it was blown. Tried replacing with new fuses and they blow immediately.

 

Is this the relay that is bad? Is it the horns themselves?

 

 

Following up. i replaced both the high and low horns and that solved the problem of the fuses blowing continually. Unfortunately when I put a new fuse in the horn now goes off constantly.

 

I out in a new airbag retaining frame from Pelican so the bushings should be good. Is it possible I overtightened it? Could the ground on the horn switch be bad?

[Loren]

Yes.

Overtightened. or broken / shorted wire or even a bad ignition switch.

[aeichmiller]

The connector for ground wire seems a little loose. Is there a source for those flag connectors? The local autoparts stores have them but with a super hard case surrounding them that will be impossible to crimp around the wire.

[drwoods]

I used #31 O-Rings and I found them in the plumbing department at Home Depot.  It worked great.  I hope this helps

[Smada]

I had an issue with the horn not working at all.  Checked the fuse and it was blown.  After reading the postings in this forum I tried installing the #31 o'rings on the airbag mount.  I was a bit hesitant that it would solve the problem as the original bushings looked to be in good condition.  The #31 o'rings fit perfectly.  I completed the install and reconnected the battery it worked perfectly.  Many thanks to all the members for the outstanding ideas and recommendations!  

[DBJoe996]

I wanted to document my project so it might help the next person.  Problem - horn honking when going over bumps.  Pulled B3 fuse until my new horn frame came in.  I noticed in some previous post they said use a T30 bit.  Mine is a 99 C2 four spoke steering wheel.  The correct bit is a T27 for the air bag bolts.  They were definitely tight so I bought a right angled tool. I ran the car and turned the steering wheel so I could easily access the two air bag bolts at 6 o'clock.  It was fairly easy.  I held on to the airbag and undid the bolts.  Turned off car and removed the key.  Gently lowered the airbag.  The yellow connector on the back of the air bag simply unplugs, pull it off and set the air bag aside.  The four bolts that hold the horn frame are 17mm and come right out.  A reverse of the procedure is all it took.  The air bag bolts must be in the back side of the horn frame, so I used some small sections of rubber hose to hold the bolts in place until I got the frame bolted in, then removed them and put air bag in place.  That was about it. The rubber bushings on the old horn frame were basically gone, thus the horn honking going over bumps.  I did not undo the battery and the air bag light did not come on after I was done.

 

Edited August 6, 2020 by DBJoe996

[JFP in PA]

Nice job, but you ran a large risk; for your own safety in the future, disconnect the battery for 15-20 min. before doing something like this.

[DBJoe996]

2 hours ago, JFP in PA said:

Nice job, but you ran a large risk; for your own safety in the future, disconnect the battery for 15-20 min. before doing something like this.

You are correct and normally I do.  Don't know why I didn't on this job since it involves disconnecting the air bag. I ran the engine so I could crank the steering wheel to get to the airbag bolts, and it all just kind went from there. Got lucky....but not a wise thing to do.

[John from PA]

On 3/5/2012 at 7:11 AM, odys996 said:

Does anybody know the torque setting of the 4 bolts for the frame, and the two torx screws for the airbag?

In doing my project yesterday I did notice that in removing the (4) bolts mentioned, they were tightened not much more than hand tight.  "Snug" would be a good term.  I'm also not sure what material they may screw into.  It may or may not be metal but even if some form of a metal bushing, the bushing is likely mounted to a non-metal portion of the steering wheel.  [Edit] I found that the Bentley manual specifies 5 #-ft (6.8 Nm) for the (4) bolts.  I also found a copy of the Porsche Technical manual and at least for MY2000 the torgue for the T30 Torx screws is specified as 7.5 #-ft (10.2 Nm).

 

There was no indication of any thread locking material on (3) of the bolts, but one had some residual of a red material.  There is a red Loctite but it is for high strength high temperature applications.  When I replaced my bolts I simply used clear nail polish.  I also used clear nail polish for the (2) bolts that hold the air bag on.  As a mechanical engineer, I'm reluctant to use blue Loctite on small fasteners, especially when they are recessed into a blind hole.  Strip the head on one (as someone mentioned they did) and you have a serious project on your hands.

Edited August 14, 2020 by John from PA

[JFP in PA]

34 minutes ago, John from PA said:

In doing my project yesterday I did notice that in removing the (4) bolts mentioned, they were tightened not much more than hand tight.  "Snug" would be a good term.  I'm also not sure what material they may screw into.  It may or may not be metal but even if some form of a metal bushing, the bushing is likely mounted to a non-metal portion of the steering wheel.

 

There was no indication of any thread locking material on (3) of the bolts, but one had some residual of a red material.  There is a red Loctite but it is for high strength high temperature applications.  When I replaced my bolts I simply used clear nail polish.  I also used clear nail polish for the (2) bolts that hold the air bag on.  As a mechanical engineer, I'm reluctant to use blue Loctite on small fasteners, especially when they are recessed into a blind hole.  Strip the head on one (as someone mentioned they did) and you have a serious project on your hands.

 

Torque spec is  44.5 inch pounds.

[mgrady52]

For my 99 Boxster, I just found a video on YouTube that walks you through an inexpensive and easy way to supplement the worn out bushings with $2.50 #30 bushings from Home Depot. Make sure you put them on in front and back of the air bag mounting plate. Make sure you leave the negative cable disconnected at least 1/2 hour before disassembly. It took me 1/2 hour and saved $300 service charge. Take your time. Getting the retaining "bolts" off (two of them) was the toughest part. Snug, DO NOT tightent the interior 4 bolts. Good luck.

[Christoph Soltau]

Great info here!

I've just bought a 1998 Boxster with what sounds like this horn problem (previous owner says horn was sounding at odd times when driving, took the fuse out).

Now just to find #31 O-rings in a metric country, or maybe that's a universal descriptor.

[Loren]

2 hours ago, Christoph Soltau said:

Great info here!

I've just bought a 1998 Boxster with what sounds like this horn problem (previous owner says horn was sounding at odd times when driving, took the fuse out).

Now just to find #31 O-rings in a metric country, or maybe that's a universal descriptor.

 

Try this...

USA Standard O-Ring Size Chart | AS568 O-Ring Sizes

WWW.MARCORUBBER.COM

---

Use the USA standard o-ring sizing chart to find Parker and AS568 o-ring sizes that work for your application. Millions of o-ring sizes are in-stock and ready to ship today. Use the o-ring size chart to find the perfect AS568 o-rings for you.

 

[Christoph Soltau]

I've just done the o-ring fix, worked brilliantly. Fuse back in, horn works evenly in all 4 corners of the wheel. My kids wanted to come test the horn too! 

Thanks Renntech members!

 

There were 4 little washers under the carrier frame. I reinstalled these using a smear of paper glue to hold them in  place while fiddling with the carrier frame and bolts. Order of assembly: washer, 1st o-ring, carrier frame, 2nd o-ring, 17mm bolt.

 

For those in New Zealand, I ordered the o-rings online from Blackwoods NZ. They have all sizes and you can make up whatever quantity you need. And they are listed in Imperial sizes so easy to find. Cost $8.50 , about USD5.

[Christoph Soltau]

Just to add, I left the airbag connected. Everything is accessible and there is slack on the airbag cable to cradle it on your lap that I don't believe you need to disconnect it unless you want to take the carrier frame out.

[way2fast91]

A note for those having trouble getting the two T30 bolts undone, I picked up a 99 C2 and was needing to replace the frame.  I spent nearly 3 hours trying to get the bolts to budge with a T30 tool I picked up.  Tried gripping it with vise grips, tried soaking each with wd40, but they wouldn't budge and seemed to be starting to strip the heads.  Was starting to consider other options, such as cutting into the side of the wheel material and either gripping or grinding the heads of the bolts or possibly taking it to a shop for Pro help.

 

What I did was pick up a 3" T30 impact driver bit and borrowed an Impact driver from a friend.  I turned the wheel so that the bolts were in the 6 o'clock position (most clearance available) and hammered the bit into the head of the bolts.  Then slide the impact driver onto the end of the bit and was able to break them loose finally.  The right tool makes all the difference.