Beetle Horn Troubleshooting

A 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 current 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.

One 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.

What to look for first. Volkswagen used a diaphragm 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.

Move 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.

Using the diagrams below will help you trace the circuit as it feeds through the steering column.

Through 1959 Deluxe models, through 1965 standard models
Current flow begins at the steering box, which is jumped over the rubber steering coupler by means of a copper wire, then flows up to the column. When the horn button is engaged, current flows from the column through the horn button and into the wire attached to the button. This wire terminates on a copper sleeve/ slip ring, which is insulated and wrapped tightly around the steering shaft. From this copper sleeve current continues on through a carbon brush that presses against this sleeve through an opening located on the side of the steering column. The wire attached to the carbon brush, brown in color, carries the current directly to the horn and thus completing the circuit. Most of the problems with this circuit are traced to the ground, which connects horn button to the steering wheel. The horn button relies on the tension of its retaining clip to provide an adequate ground to the steering wheel. Always make sure that this clip and the surface inside the steering wheel hub is clean to provide for proper contact. This is a common problem with steering wheels that have been painted in that this area was not masked prior to paint application.

1960-1961 Deluxe model Beetles
This was the first year of the dished style wheel. Almost everything about these two years is unique when it comes to the horn circuit. The principals of this circuit are basically the same as 1962-1967 (which we will mention next). Instead of using a wire to run current from the horn button down the column to a ground source, the steering shaft itself was used as the electrical conductor. This meant that the tube and the shaft would need to be insulated from each other. VW did this by using plastic spacers and shims. Don’t bother calling for the components pertaining to this assembly as they are very scarce. If you need replacement parts, the best solution is to convert your arrangement to the 1962-1967 variety. You will need a steering column, steering wheel and a horn ring with attaching hardware to make the change.

1962-1965 Deluxe model Beetles, 1966-1967 standard and Deluxe model Beetles
Current flows starting at the steering coupler, steering box side, where a wire is attached and feeds through the center of the steering column to the horn button/ring. Please note that these years did not use a ground strap that crossed over the steering coupler. When depressed, the horn button feeds current to the steering tube. At the end of the tube, under the gas tank you will find a male connector. Attached onto this connector is a brown wire that leads directly to the horn thus completing the circuit. Poor connections are the usual culprit with this particular span of years. Also, insure that the chrome horn ring is mounted to the steering wheel properly.

1968-1970, all Beetle models
Vehicles used the new steering column that bolted directly onto the dash without the insulating rubber grommets as used on earlier vehicles. To compensate for this, VW added plastic insulating shells around the upper support bearing. Instead of running the wire down the column, as done in 1962-1967 years a wire was soldered to the bearing, which ran directly to the horn.

1971-1979, all Beetle models
Volkswagen made a full circle and brought back the brush and copper slip ring to transfer the current to the horn. The circuit is very similar to the 1959 and earlier layout with exception of the slip ring. This was replaced with a copper pick-up ring mounted to the base of the steering wheel. A copper plate mounted to the turn signal switch applies tension against this slip ring allowing the current to pass through. From here the brown wire directs current to the horn.

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