986 Horn Trouble - Only works when hey is not in ignition...

[bmblack34]

Ok gents...

I got a weird one I need help solving. I have a 2001 Boxster (986) and I have been having on and off again horn issues. I have been through the list of possible problems fuses, relays, bad horn, etc. and I have narrowed it down to some very weird circumstances where my horn does and doesn't work that I am consistently able to reproduce.

My horn works perfectly, before the car has started and before the key is in the ignition. However, as soon as I turn the engine on or turn the key enough that the battery light and radio come on my horn no long works until I remove the key from the ignition again.

This makes no sense to me... and I am really hoping that one of you guys who might be familiar with the wiring on my car can lend me a hand. But where the heck do I go from here? How do I trouble shoot this?

Any ideas you guys have would be extremely helpful. Thanks!

[rsfeller]

As you may have read the most common failure trend with the horn is the failure of the rubber bushings within the air bag frame on the 986 models. These tend to fail either in the on position (and thus you must pull a fuse to keep your horn from sounding permanently), no horn possible at all due to connection failure or very strange intermittent consistence. None of which should have any bearing on the ignition position.

If it's not in fact a strange coincidence then there is an issue at work with either a ground or a leaking 12v+ from the system. Maybe an electrical expert here could explain how this could happen. Since the the horn tends to recieve a voltage all the time it makes me think you may have a ground issue but I'm not sure how the airbag/bushing failure could play into this.

Obviously I'm doing a lot of speculating here that may be of no use. I would truely start with the common bushing failure before going to far. Are you sure it is the ignition that is the connection and not the fact the wheel is unlocked or turn and then messing with the connection? I cannot recall how the "clock spring" plays into the horn on this car.

I'm done talking smack.

Edited March 28, 2008 by rsfeller

[Loren]

Someone else had this same problem - do a search.

As I recall it turned out to be a broken wire in the steering wheel switching.

[bmblack34]

Loren knows all :) Thanks!

I did a search for "Steering Wheel Switching" and came up with a boatload of previous posts with the same issue. This thread here has links to a number of them.

http://www.renntech.org/forums/index.php?s...wheel+switching

Thank you guys. Sorry for not digging this one up on my own first.