|C4 Horn Repair|
Date(s): June 20 2013. Album by Power Wagon. 1 - 8 of 8 Total. 1420 Visits.
|I recently bought a 95 coupe. The only problem was the horns did not work. Rather than buy new horns and pay the Corvette Tax, I decided to do surgery and repair them. The first horn took a little over a hour start to finish. The second horn did not take over 20 minutes since I knew exactly what was inside and how to attack it.|
Water getting into the horns created terrible rust. The rust seized the contact points and even filled the electro magnetic hole. I bead blasted everything on low air pressure and then started the rebuild.
Before we can rebuild, we must know hoe the item works so we understand what each part is doing. The horn is very simple. Think of it as one of the handheld crickets little kids have to squeeze and click. The big difference is this is electric powered and operates at tremendous speeds to generate the sound.
The outer shell with the actual plastic shaped mouth that the sound comes out of is the final part of the amplification. Behind the output mouth, there is a intricate passage way of channels that the sound travels through. Not being a sound engineer, I dont understand the different size passage ways and shapes. Never the less, this part only needs wiping out. Its plastic and no rust. There is a metal diaphragm that actually creates the sound much like the cricket mentioned earlier.
On the back side of the diaphragm is a steel protrusion about .500" in diameter and
roughly .500" long. This piece fits down in the hole which is wrapped by an electro magnetic.
There is a set of points, much like on a point ignition system, but with a small tab sticking out on the electro magnetic side. When the horn is off, the points are closed due to spring tension on the adjustable arm. When you blow the horn or the alarm system activates the horn, 12 volts is applied tot he electro magnetic coil, thus drawing down the diaphragm, which makes the click sound. At the bottom of travel, the metal piece riding in the electro magnet hole comes in contact with the small tab which is part of the points. The points are forced open,
the magnetic field ceases and the diaphragm returns up clicking again. On the trip up, the points close and the diaphragm is once again pulled down clicking. This happens at super fast speed. The faster the diaphragm moves the higher the pitch of the sound.
On the back side of the horn is a small adjustment screw, that varies the tension on the points. The more tension, the faster the speed = higher pitch. Less tension = slower speed and lower pitch. Thats all there is....simple....now lets fix the rusted up horn. Follow the pictures and the descriptions under each picture and you will do well. The fix is FREE and there is no Corvette TAX.
Double click on the first picture to go to full screen, then you can use the arrows to advance thru the pictures/descriptions.