Am I missing something here? Horn button assembly

[slatgrille]

I was able to remove the horn button from the steering wheel on my '48 P15 and it was all clean inside, no chaffing or broken parts. Other than the horn wire having a yellow plastic insulation, all appears original. The bottom cup, large spring, 3 pronged brass bar with horn wire attached to center hole, horn ring, and center ornament were all present. Before removing the brass bar, I turned the ignition on, and sure enough, the horns started blasting. It took me awhile, but I think I have figured out how this system works. Please correct me if I'm wrong.

 

The horn wire is 'live' against the brass bar when the large spring makes contact with it from underneath. The horn ring depresses the spring in 3 locations preventing it from contacting the bar until it it pressed at an angle. 

 

Before assembling, I held the ring in the depressed position and turned the switch on again. Horn started blaring! The only thing I can think of is that some sort of insulator is missing that prevents the ring from making contact with the bar causing and complete circuit. Is there any way to make the ring insulated from the bar? Am I missing a part?

 

Thanks in advance for any help provided.

 

Craig

[harmony]

As you mentioned, there are the 3 screws holding brass fitting in place.  But you didn't mention the centre piece that holds the horn ring in place and that the centre chrome piece snaps into with the 3  super long machine screws.  That's the piece that you have to push down hard on it to compress that spring with one hand while you start threading in those super long screws with your other hand.  Do you have that piece?

I found that all the screws have to be super tight. However in an earlier thread 2 or 3 months ago someone had a similar problem and someone said that they got the horn to stop blaring once the ignition was turned on by loosening one of the brass screws ever so slightly.  

Edited May 6, 2022 by harmony

[harmony]

This is the piece I'm talking about

[slatgrille]

Here are some pics to better explain my issue. (Since my PC update, I can't figure out how to shrink them. My 'ancient' Vista software I had no problems, Windows 10 is different.....) Sorry ?

 

Pic #1

[slatgrille]

Pic #2

[slatgrille]

Pic #3

[slatgrille]

Pic #4

[slatgrille]

Pic #5

These are the parts I've got and their placement in the system. Seems I'm missing something?.......

[Plymouthy Adams]

that did not work....????

Edited May 7, 2022 by Plymouthy Adams

[busycoupe]

The horn button grounds the wire coming up the steering column. If the horn blows with the center button off then you should look for a short in the wire.  You said that the center wire is yellow plastic covered; that is not original.  Someone must have had the same problem at some time and replaced the original wire.  The plastic covered wires aren't as flexible as the original and may have developed a warn spot in the insulation inside the column.  You can replace this wire by connecting a new wire to the old one at the base of the column then carefully pullining it up from the top of the column. 

[slatgrille]

I ask about this because when I depress the large spring with my fingers and turn the switch on, there is no contact so the horn is quiet. Let the spring touch the brass bar and off the horns go. That's why I think there should be some sort of insulator between the horn ring 'slots' and the brass bar....to prevent metal to metal contact when the unit is assembled.

[DonaldSmith]

How the horn ring works:   (Not what you would think.)  Look at Pic No. 1  above.  

 

Yes, the spring is contacting the Tee-shaped thingie with the end of the grounding wire.   Yes, this grounds the circuit.  Sustained  Honk. 

(Disconnect the ground wire from the horn relay, or under the steering box, to keep from driving yourself and the the neighbors crazy.  You can connect a bulb in a circuit from a power source to the ground wire, to tell when the horn wire is grounded.)  

 

The ends of the Tee are fastened to a plastic molding, and thus are insulated from the ground.   The tee has to contact the spring to ground the circuit.   

 

What keeps the spring and the tee separated are lugs on the horn ring. (The horn ring is also insulated from ground.)   Push the horn ring in one location, and the opposite side pulls away from the spring, allowing that part of the spring to contact the Tee.  Honk.  

 

 

[slatgrille]

The problem is...the slots in the ring that go over the brass prongs are in contact when the edge of the slots touch. Should I insulate the ring slots with electrical tape to prevent inadvertent contact?

[DonaldSmith]

Let's look at an assembly that is working right. 

 

At rest:  The cap, pics 4 and 5, is screwed tightly to the non-metallic ring, pics 1 and 2.  This draws the 8 lugs of the horn ring, seen in pic 3, against the spring.  The horn ring and its cap in themselves are isolated from ground, since they are fastened to the non-metallic part of the steering wheel, seen as ring-shaped in pics 1 and 2.  The spring is kept from contacting the brass tee, which connects to the end of the grounding wire.   (For fun, contact the horn ring with a grounded wire; the horn will sound.) 

 

To sound the horn:  Press the horn ring forward, and it rocks the  lugs. The lugs opposite the pressure are lifted away from the spring, so that the spring in that location can contact the brass tee.  Circuit completed.  (Pull part of the ring backwards, just to be different; the horn should sound.) 

 

The lugs of the horn ring should not touch the sides of the brass tee.  Things would have to be out of alignment for that to happen. Anything look worn?  The design of the ring and cap should keep enough gap between the lugs and the brass. 

 

Do the clips in pic 5 extend too far and contact the brass tee?  Not likely.     

 

Late Night Edit:  Grounding:  Necessarily, the brass tee is not grounded, being screwed to the plastic of the steering  wheel.  Immaterial whether the horn ring is naturally grounded.  It is grounded when it contacts the spring, which is always, once everything is assembled.    Let's sleep on it.   

Edited May 8, 2022 by DonaldSmith
corrections

[slatgrille]

I'm about to go tackle this again in a few min. I'll hold the unit together by hand and see what happens. If the horn goes off again I'll figure out a way to insulate the ring slots and maybe the 8 lugs. I'll check in here off and on, then report results if I solve the issue.

 

Thanks again for the help!

 

Craig

[slatgrille]

As promised, here is the result. To keep it short and simple, I put the button assembly back together and it works as if nothing was ever wrong! I surmise that the 3 screws holding the center piece on were too loose. Sounds simple but except for 1 screw, the other 2 were easily removed. They need to be tighter to keep the ring pressure against the large spring. Being loose allowed the spring to make contact with the brass bar. Amazing what just a little 'tweaking' can do!

 

Can't say I'm a fan of the whole set up. Much easier if they just had a center button with a ring that made contact when depressed....like my jeeps. Oh well, learned something new today. Thank you to all with your comments and suggestions. 

 

Craig

[DonaldSmith]

Good job.  We knew you could do it!

[andyd]

The horn button on our 30's & 40's mopars is an earth switch..ie, pushing the ring/button or whathaveyou earths the circuit and the horn toots...........there should usually be a relay wired into the circuit going to the horn/s also...........andyd

[slatgrille]

Yes, I actually replaced the relay too since the original had broken insulation.