>Date: Tue, 17 Nov 1998 08:32:05 -0800
>From: "Nelson, Mark J" <Mark.Nelson_at_JSF.Boeing.com>
>Subject: E34 Horn
>
>My horn is inoperative because the steering wheel is not grounded with
the

>ignition ON . Interestingly, the wheel is grounded with the ignition
OFF.

>In fact, the ground is lost when the ignition lock cylinder is pushed
inward

>(even without the key). I know that the rest of the horn circuit
(including

>the contact ring) is working properly because the horn honks when I
manually

>ground the horn wire in the steering wheel.
>
>This problem has existed since I bought the car a few months ago, so I
can't

>say how it might have occurred.
>
>Thank you in advance for any light you can shed.
>
>Perplexed,
>Mark Nelson
>Seattle, WA
>92 535i 130k mi
>BMWCCA No. 161283

I ran across this problem in an 8 series once. Can't remember if the 5 series column is set up the same but there was a rubber coupling in the column, inside the car (to allow for wheel tilt) and the ground lead that circumvents this was broken.
In order for the horn to work, the centre of the steering column must be grounded. Your steering lock is doing this when the ignition is off. The centre of the steering column is grounded at the steering box, so it is simply a case of moving backwards from there to find out what is missing.

Brett Anderson
BMW and ASE master technician
http://frontpage.bestweb.net/~bretta

Please include all correspondence when replying to avoid confusion - Thank you

.