Why does horn in 2004 rendezvous sound terrible?

Answer 1

"Off-Tone" Condition in Automotive HornsUsually, off-tone conditions are the result of the vibrating switch contacts [INSIDE the horn] being out of adjustment.

In order for a horn to operate, the DC [Direct Current] MUST be converted to a pulsating [constantly turning on and off while the horn button/switch is depressed] in order to vibrate the diaphragm inside the horn. It is the vibration of the diaphragm that creates sound waves that come out of the horn.

This needed pulsation in the DC current is created with a switch inside the horn that vibrates, thus making and breaking the DC current into pulses. The duration and rate of these pulses is what determines the quality and loudness of the horn sound.

Not all, but some, horns have an adjustment screw on the back side of the horn body. Those with no adjustment screw must be replaced when the vibrator switch becomes out of adjustment/defective.

For those horns with an adjustment screw, you can readjust the vibrating switch contacts to improve the quality of the horn sound output.

The adjustment screw is slightly different from most screws you're used to seeing. Horn adjustment screws generally have NO Head, but instead only a small "slot" in the top of the screw shaft. Around, and at the base of, where the adjustment screw enters the horn, there will be a NUT which when tightened down will "lock" the adjustment screw in place, thus preventing the screw from vibrating out of adjustment.

To adjust the vibrating switch you will need a small screwdriver that snugly fits the slot in the screw, a small wrench to loosen and re-tighten the locking nut, either ear plugs or sound absorbing ear muffs to protect your hearingduring horn adjustment, AND an ASSISTANT/HELPER to hold the horn button/switch depressed [ON] while you adjust the horn for optimum sound output.

• To make the adjustment, insert the screwdriver into the slot on the screw to keep it from turning while you use the small wrench to LOOSEN the locking nut.
• With the locking nut loose, have your assistant blow the horn. Be sure to have ear protection as being that close to a blowing horn can cause hearing damage.
• While the horn is blowing, very gently, and very slightly at a time, turn the adjusting screw back and forth until the sound coming out of the horn is at its maximum loudness [and hopefully optimum tone].
• When the horn sound is at the optimum, continue to use the screwdriver to "hold" the adjusting screw to prevent changing of the adjustment you just made, and
• Tighten the locking nut to "lock in" the adjustment setting.

Whew! It takes longer to write or read these instructions than to make the adjustment. Good luck.