The stock horn switch is a pushbutton, that also doubles as the high/low beam
switch. The horn section of the switch is a contacting area around the
very central barrel area inside, touched by part of the black pushbutton (tiny
The pushbutton has a metal shaft going into the switch area. On that small
round shaft is a C clip (or E-clip). That little tiny Jesus Clip (you KNOW why
it is called that ) will fly out, across the garage, never to be seen again,
after you carefully pry it sideways, off the shaft using a very tiny jewelers
screwdriver, or similar small tool. DO NOT loose it, and do NOT deform it
by being ham-fisted.
Put a large old white bed sheet around the area, to capture the flying
clip .and the spring, etc. Murphy's laws say that the clip and spring will fly
out OVER the bed sheet, and that they will never be found again .and that
you will never figure out how the internal contact is refitted anyway. If you
are an old hand with this, you will not have things flying. Remember, flown
parts need to be eventually returned to rightful positions!
****Be exceedingly careful about removing the clip it is done by having
THREE hands (just kidding) and the push button needs to be pressed INwards at
the same time. I might be able to do it with my two hands (I do), but YOU might
want to fashion a method of SECURELY keeping the pushbutton pressed inwards. Remember, this is all done while the outer switch is dangling from its wires,
having been unscrewed from the bar switch holder!
Pressing the button: Doing that will immediately show you what I am talking
about, as the C-clip moves right along with the shaft.
Have any and all battery negative wires OFF the battery post FIRST.
****Under the push-button is a brass-looking funny irregular and bent up
piece of metal that is the contact(s) for the lights portion. That will come out
and you will spend a lot of time figuring out how it fit, when you replace
it UNLESS: you remove the E-clip carefully, button pressed-in (some), and very
SLOWLY remove the pushbutton, NOTING the exact position and method the brass
rotating part fits.
Be sure to note which side is up, and the orientation.
****There is a SPRING under the push button cap it is light and thin and easy
****When into the switch, clean all contacts with some solvent, dry them,
burnish all contact parts with a good pencil eraser, and use a faint smear of
silicon grease on the contacts when reassembling. This makes it especially
nice fun with slippery fingers to get the spring and C-clip and internal wiper
parts all back together without a lot of cussing.
Give snowbum a thank you email. He has written many good articles for the
airheads list. Go
to his personal web site
for more outstanding BMW info. On any issue related to BMWs after 1975,
believe him, not me.