Kip is one of those guys who has keep this place a fun and informative place to be. He's been with us a long, long time. And has provided us with a nice stack of Tech Tips:
Bolters Building the Site! Thanks Kip and thanks for the update! ~ Editor
It's all well and good to be safe. And letting people know you're there with a gentle blast of the horn is a great way to do it. But there's also something neat and complete about the nostalgic bark of these old 6-volt vibrating horns! And they do complete a restoration. Hard to do? No way! Here's Kip to show you that your name doesn't have to be "Horatio" to be a horn blower. You just need a little time, patience and the right parts to...
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Get that ole horn blowing!
When I first brought my 1941 Chevy 3/4-ton home, there was a fair sized mess inside the cab. The dash was laying half turned over on top of the steering column and all of the center stuff (horn parts) were missing. When the truck was placed here in the Gallery, I really had no idea of how the horn was supposed to work or even what parts made up the whole unit. It did not help much when I bought a steering wheel that it turned out to be a 1939 / 1940 which had a totally different center hub from the 1941and required different horn button parts.
At this point I was really confused. With a lot of help from the Bolters on this site, especially Dad6timz, Brendan M, George "46forme" Wells, and TWEAK, I got the whole thing figured out
So Here Goes…
There are some good wiring diagrams at The Old Chevy Manuals Project site!
The horn is hot all the time. When you push the button in the center of the steering wheel, you complete the circuit by grounding the horn. The horn is mounted to a boss cast onto the intake manifold with two 1/4" bolts. The bracket between the horn and the intake manifold is electrically insulated. The metal parts of the horn do not connect to or touch the manifold where they would be grounded through the engine back to the battery. There is a wire (I used 10 gauge) from the battery side of the amp gauge directly to one of the terminals on the horn. I don’t think it matters which one. Just be sure the wire or any terminal end you use doesn’t touch the large dome shaped horn cover. This wire allows current to go to the horn without going through the amp gauge or any other device including any fuses.
On the original unit there was no horn relay. (Guess in the '40s people did not drive with their horns.) The other half of the circuit is a wire (again, I used 10 gauge) that connects the other horn terminal with the upper mast bearing just under the steering wheel. There is a hole in the bottom of the steering shaft cover just above where it clamps to the steering gear box. Yes, it's really there -- it's just filled with grease. This is where the wire comes out and proceeds to the horn. The wire runs up inside the steering shaft cover, up to that little bearing at the top (mast bearing) that keeps the shaft aligned in the center of the cover just below the steering wheel. The wire is soldered to the outside of the bearing (you will see a small indentation where it is to be soldered on). The bearing is actually hot all the time as the wire coming from the horn is hot. The bearing is insulated from both the shaft and shaft cover with a VERY thin layer of bakelite. (Photo # 2 / Mast Bearing)
Steering Wheel & Assembly
Because I do want to drive my truck before I get too old, it is not a “frame up” restoration. Since the cab is still in place, the steering shaft cover will not come completely off. It hits the inside of the cab roof. It did come far enough up to get a good cleaning and allow me to find that hole where the horn wire comes through. I dropped a fish line with a small sinker down between the steering shaft and the cover. Once this came out the bottom, I fished it back through the hole in the shaft cover. The next step was to use the fish line to pull the wire down from the steering wheel end and out the hole.
The next step was understanding the steering mast bearing. I bought a new one and at first look, I still did not see that it has electrical insulation over the areas that touched either the steering shaft or the shaft cover tube. The bearing came with a short length of wire already soldered to it. Using this wire and a simple continuity checker, I finally figured the insulation out. The only part of the mast bearing that is not insulated is both ends (faces). After connecting my new wire to the one that came soldered to the bearing, I was ready for a test. By touching the mast bearing’s brass upper face to any ground, I could get the horn to honk !!
So now the steering shaft cover tube, complete with bearing and wire, can be slid down the steering shaft, fitted over the hub on the steering gear housing and clamped in place. Once this is done the “U" bolt clamp holding the shaft cover tube to the bottom of the dash can be installed and tightened. The center of the steering wheel / horn button assembly is shown here. I received this from one of the Bolters mentioned above.
Before starting, disconnect the wires from the horn so you don’t have it going off during the steering wheel assembly. First piece is a bare spring that slips over the steering shaft and sits against the face of the mast bearing. Then the conical shaped piece with the three prongs facing the driver. And next a rubber ring that looks like a gasket. (photo #5 / Parts in order of Assembly) Now the steering wheel, carefully so each of the three prongs slips through one of the small 3/8" diameter holes. Now is a good time to make sure the front wheels are straight and the steering wheel is in the position you want. (I’m not sure if it is supposed to have one spoke vertical at the top or at the bottom.)
Next, the other spring then the brass saucer shaped plate, Be sure that the three prongs that are coming up through the steering wheel are each nested in a notch in the brass plate. Now the fun starts. You have to hold upward pressure on the conical piece with the prongs while pushing down on the brass plate while trying to insert the large diameter wire spring clip over the three prongs and under / into the very little notches in the brass saucer piece. Good luck !! (photo #6 / Brass Saucer and Retaining Spring. Enlarged image.
Next, you get to try to line up the small threaded stud on the back side of the horn button with the small hole in the brass plate all at the same time that the horn button is slipping out of your fingers into the recess in the center of the steering wheel.
Now you are done !! So sprint around to the front of the truck, place the wires on the horn, quickly back to the cab and press the horn button and ……. dead silence .
Man you don’t want to take this thing back apart again, so pay attention. The horn should work because you are grounding it. That ground goes through the mast bearing’s front face. Did you clean it off when you installed it??
The ground then goes through the bottom face of the conical piece. It needs to be rust free and unpainted.
Next it goes through the three prongs to either the steering wheel at the three small 3/8” holes or through the brass plate to the top of the steering shaft (I never did figure out which). Any way the point here is the steering wheel and shaft have to be unpainted and clean in these areas.
There is one more thing. If you positioned the steering shaft cover too far down onto the boss on the steering gear, there will not be enough travel in the horn button to push that conical piece far enough to contact the top of the mast bearing. If this is the case, just loosen the lower clamp and the “U” bolt under the dash and slide the whole steering shaft cover up towards the steering wheel an eighth of an inch or so.
That’s it your done. Image #7 / Finished Assembly.
PS -- A while back, I received an e-mail from someone named Joe asking how a 1941 / 1942 horn works. I responded with some information and asked Joe how he came to get my email address. He answered that he had seen it in the Stovebolt Gallery. At about this point, I noticed that Joe's e-mail address included the name of a nearby town. A few short notes later, we determined that we were in the same High School class and graduated together 44 years ago. It just so happened that I was in the process of clearing out my Mother's house where I found my high school year book. The book was lying on my desk when Joe's e-mail confirmed the high school information. Sure enough, there he was! We also found out that we attended the same university.
Well, we met on a Saturday for lunch with much to talk about. Joe is the first classmate that I have met since graduation and the first "Bolter" that I have met in person. All thanks to this site.
Money isn't everything but it sure helps in the land of Old Iron.