malfunctioning horn is a dilemma that every Beetle owner
encounters sooner or later. The diagnostic procedures used
to troubleshoot horn circuit problems are basically the
same as most other electrical components on the Beetle.
There is a source positive electrical current, a source
for negative current, and a means to connect the two in
order to actuate the particular device. What makes the horn
circuit unique is the way in which the current flows to
the horn. When you visualize an electrical circuit, you
probably envision a wire which carries positive energy,
and a wire or contact point to carry negative energy. In
the Beetle horn circuit, the steering column (the actual
tube that you see under the dash) is also used to carry
the negative cur- rent from the steering wheel to the horn.
The idea that the tube is used as a conductor is no revelation.
It is understanding the flow of current in the circuit that
makes pin pointing the ele- ctrical problem much easier.
note before we move on. Bus owners are spared many of the
headaches listed below as the horn activating circuit consisted
of a wire running from the button to the horn. It doesn't
get much simpler. Although some of the tips we provide below
do apply to the Bus, this information is truly directed
towards the Beetle.
to look for first. Volkswagen used a diagram type horn that
consists of two elec- trical connections. There is no polarity
on this type of horn so either terminal can accept the positive
or negative wire. Before pulling out the test light (resembles
an ice pick and has a wire protruding from one end of the
handle) take a minute to visually inspect the horn, its
connections and the fuse box. Make sure that all of the
fuses are in place and clean. Always replace fuses that
are questionable. Next have someone hold the horn button
down while you check for voltage at the horn itself. First
check the terminal that has the black wire with a yellow
stripe, this is the positive wire. If voltage is not present,
trace this wire back to its source, the fuse box. Check
both sides of the fuse. Current is supplied directly from
the battery to this point so you should find voltage on
both sides of the fuse.
back to the horn. With your assistant holding the horn button
down attach your test light alligator clip to the black/
yellow wire while pressing the ice pick end onto the brown
wire. The presence of voltage here suggests that the horn
is at fault. The lack of voltage indicates that the wiring
leading from the horn through the button to ground is faulty.
We find that next to replacing the horn this is the most
common fault in the horn circuit.
the diagrams below will help you trace the circuit as it
feeds through the steering column.