68 C10 Horn Button Assembly Order

[nickmomrik]

I recently bought a 68 and the owner had the horn wired to a button where the choke was. I'd like to rewire it back to the steering wheel, but I'm having a hard time determining the order of assembly. It seems like I've tried everything. I can get the relay to fire when connections are made, but I can't get the proper pieces put on so that the steering wheel button is actually pressable. At times the button won't even connect into the cup and other times, it fits on, but it's tight so can't be pressed.

I've tried the order described by LockDoc at http://67-72chevytrucks.com/vboard/s...d.php?t=426902 but then the button won't even go on. I think part of my problem may be I'm not sure when the washer and nut for the steering wheel should go on in the process and not sure if the washer is possible too large.

The previous owner gave me a box of parts and I think there are pieces here from multiple different years of the C10, which makes it all so much more confusing, especially when trying to compare to the LMC Truck catalog, which seems to be wrong from what I've read.

I'll attach a couple of pictures showing what I have.

Any help would be awesome! Thanks!!

[68 P.O.S.]

The horn button only goes on 1 way. In your 1st pic, the metal cup the horn button presses into, see that notch at the top of it? Your horn button rubber has a notch that fits in there. So, leave the nut and washer off for now. In your 1st pic, the metal disc on the bottom right, put that inside the steering wheel, dome side up. Next, the metal cup goes in on top of the metal disk. Make sure you pay attention to where the notch on the cup goes, or you'll be taking it apart again to straighten your horn button. Next, align the holes on the disk and cup. The red ring with the 3 holes goes in the holes you lined up and holds it together. Insert screws, tighten, add your big washer & nut, then the horn button and you should be in business.

[nickmomrik]

Thanks. I've tried that many times and just did it again from scratch, which is why something just seems off. When I assemble it like that, the rubber piece on the button is too far away from the metal cup and the button is already hitting the steering wheel edges, so it won't even fit in and just falls off.

Is it possible this steering wheel button isn't deep enough? It's a little hard to measure but it's about 7/8" from the back side of the button to the end, when the rubber is off of it.

[dmjlambert]

But first....
start with the white ring with the tower sticking up (part 4). I believe one of the pins (part 2) goes into the tower, then a spring (part 1), then a pin (part 2) so a pin is sticking up above the tower top and is springy and can compress down into the tower. I think one of part 3 may be a retainer to hold that assembly together. I don't think that is normally taken apart, so it has been a while since I saw it apart. I had to take mine apart once to clean the contacts inside, but I was careful and re-assembled it right away before I could forget what order they went in.



Before putting other stuff together short with a screwdriver the steering column (part A) to the pin (B). That should honk the horn or click the relay if you have disconnected the horn under the hood. No point to go any further if the screwdriver shorting does not activate the relay.



Then...
The ring with the white tower goes on the steering column first. The bottom of that ring is metal and makes contact with pin (B) and then the steering wheel goes on, with the tower sticking up through the steering wheel hub. After you get that far, use a screwdriver to short the steering column to the pin that sticks up from the white tower. That should honk the horn or click the relay if you have disconnected the horn under the hood. No point to go any further if the screwdriver shorting does not activate the relay.

The pin that sticks up from the white tower makes contact with the convex spring which is one of the next parts to put on.

I think you have too many parts.

[nickmomrik]

Thanks @dmjlambert. Yep, looks like I've been assembling the turn signal cancelling cam correctly as well. Once I've connected everything, I can trip the relay by touching a screwdriver between the metal cup and the screws that hold it in. I can also trip it if I get something and push the metal cup down into wheel, simulating what the button would do.

Here is a picture of it assembled. It's just too deep in there for the rubber of the button to fit on to the metal cup.

[dmjlambert]

Maybe you don't have too many parts, there are just more parts than I know. I admit I have not put together 67-68 horn button, I have a 69. Here is a picture from the LMC catalog, maybe that will help. It looks like just one pin goes into the tower.

[LockDoc]

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There are two different metal cups for the horn assembly. The '67 and '68 cup is 1" tall and the '69-'72 is 3/4" tall. You may have the wrong one.....

LockDoc

[nickmomrik]

Oh wow. Yep, mine is only 3/4"!

[68 P.O.S.]

Originally Posted by dmjlambert

But first....
start with the white ring with the tower sticking up (part 4).

Good catch on the canceling cam. I forgot to address that.

nicmomrik, so did you install the canceling cam that dmjlambert labeled as #4? That may be where the extra space is coming from. Been a min since I've been in there

Never mind, too slow lol

[dmjlambert]

Is that extra hardware in the LMC catalog shown above something that goes in a stock 67-68 setup, or is it extra stuff they are making available to give another 1/4 of spacing so the 69-72 cup will work in a 67-68 wheel?

[nickmomrik]

I did try the clear spacer and clear ring for the screws and it did get me some space to be able to attach the button, but still not enough for it to press enough.

[dmjlambert]

I think the right answer will have to come from somebody who has seen the stock innards of a 67-68 wheel, and if it does not include that extra spacer it would be good to hear from somebody who has purchased that and used it. It could be a matter of getting things put together in the right order. There are some things I can't image where to put, such as that white pin with brass or copper ends, which is also shown in the LMC picture. It is also not clear if you are supposed to use one convex spring disc or the other, or both.

If all you are lacking is a 1/8 of an inch or so, you may be able to add a spacer of your own made out of a sheet of plastic, metal or wood, to hold the cup higher.

[nickmomrik]

I had been thinking about that, but when I use the clear plastic pieces I'm already running short on space for the washer and nut on the shaft, and the threads are in rough shape as it is. I needed to order a few things so I ordered the deeper cup. I'll report back when it comes in and I try things out.

If anyone does know the correct order for those spacers and the cup, since the LMC image doesn't show where the cup plays in with those pieces that would be super helpful.

Thanks everyone!

[jjzepplin]

Subbed for knowledge.

[LockDoc]

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Here is a picture of all the pieces needed for a '67 & '68 horn assembly. Nothing else is needed except the horn button.

LockDoc

[nickmomrik]

Thanks LockDoc! I had found a couple videos of people taking apart a 67 and 68 and the parts lined up with your picture as well. Looking forward to the other cup coming in so I can try it out!

[jjzepplin]

So the pin on the canceller provides the connection to the relay. The plastic piece holds the spring loaded type disc and cup off of it? then when the button is pressed it makes contact with the pin?

[dmjlambert]

The spring loaded disc outer edge sits on the plastic of the steering wheel and that spring disc is in constant contact with the pin on the canceller, and the cup that holds the button. So the whole assembly is connected to the relay negative terminal. When any part of the button or cup is pressed, the spring loaded disc inner hole edge snaps down and makes contact with the metal raised portion of the inner steering wheel hub near the steering wheel nut, and that connects it to ground. That is what activates the relay.

[jjzepplin]

Oh jeez thank you! I have not put mine together yet but this will save me a bunch of time.

[custom10nut]

Great info. I need to replace my cancelling cam and this will help

[67chevemall]

Originally Posted by LockDoc

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There are two different metal cups for the horn assembly. The '67 and '68 cup is 1" tall and the '69-'72 is 3/4" tall. You may have the wrong one.....

LockDoc

BINGO...That is my problem too. Thanks
Don you have an extra 1 inch one?

[67chevemall]

Originally Posted by LockDoc

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Here is a picture of all the pieces needed for a '67 & '68 horn assembly. Nothing else is needed except the horn button.

LockDoc

So the fat spring in his very first picture. Upper right side.. is not needed for 67 68?

[LockDoc]

Originally Posted by 67chevemall

So the fat spring in his very first picture. Upper right side.. is not needed for 67 68?

Nope, only the parts in the picture I posted.....

LockDoc

[67chevemall]

OK thanks. I am good except for the cup I have in not 1 inch.
I didn't think I would have to glue the button on.

[nickmomrik]

The taller cup sort of did the trick, but I needed just a little bit more clearance. I made some plastic washers to go with the pink piece. Then due to raising that height, I also needed a spacer between the spring and the cup. I put together a video, which will hopefully help others who Google for this in the future.

https://nick.blog/2018/06/24/1968-72...tton-assembly/

Thanks for everyone's help!