Horn confusion

[Kwlittle]

Folks

I'm restoring a 69 and removed the steering wheel and column switches some time ago to chase some wiring issues. As part of those activities, I had to replace the (I guess) original column switch assembly with a newer one. All that is cool, but now I can't figure out how to reassemble the horn spring, etc! On the newer column switch, there are two horn contacts. If you jump across them with the steering wheel removed the circuit is completed and the horn works. Fine. The back of the steering wheel has a brass ring that I guess is supposed to make contact with these contacts when the horn button is depressed? But the steering wheel is clamped down securely on the steering shaft so obviously it does not slide up and down making and breaking contact. On the front side of the wheel is a raised brass ring that has continuity with the brass on the back side. The back of the horn button itself also has a brass ring that will touch this other ring when horn button on is depressed. But, it would seem that if the two contacts are already making contact with the brass ring on the back, the circuit is complete all the time? I'm just not seeing how depressing the horn button on affects anything on the back side of the steering wheel ...

Obviously I'm missing something. Any help is appreciated.

Thanks.

[vandor]

> On the newer column switch, there are two horn contacts. If you jump across them with the steering wheel removed the circuit is completed and the horn works

Are you sure about that? It's not how it's suppoosed to be. Both contacts are supposed to go to the same wire that goes to the horn relay. When you press the horn button the contact ring on the steering wheel is grounded, thus grounding both of the contacts on the steering column switch.

[Kwlittle]

Csaba

Yes, that's the situation. If I jump across both contacts, the horn works. the left contact is hot -- if i jump it to any ground the horn works. Not so for the right contact, which seems to be a ground.

Keith

[vandor]

Weird. Maybe just disconnect the right contact from the ground? Hopefully it has it's own separate wire.

[VAspider]

On my 69 I have one going to ground the other is power to the horn. Wire should go from the combination switch to the underhood lamp to the fan relay then to the horn relay and on to the horn compressor. Wire colors from what I remember are purple from switch and blue from horn relay to horn compressor.

[spider2081]

On my 69 I have one going to ground the other is power to the horn. Wire should go from the combination switch to the underhood lamp to the fan relay then to the horn relay and on to the horn compressor. Wire colors from what I remember are purple from switch and blue from horn relay to horn compressor.

I don't have a wire diagram for a 69, however reading these posts I think this is correct.
The contact below the steering wheel that is testing to be positive 12v is the wire that activates the horn relay. This wire gets switched to ground by the horn button. Power for horn is connected to the horn relay contacts and to the relay coil. The other side of the coil is the wire that has voltage on it at the steering column. When this contact is grounded the horn relay is energized and power is connected to the compressor.
I think the original question is how to get the mechanical part of the old horn button to work with the newer style column switch. Maybe posting some photos of the new and old mating parts would help

[Kwlittle]

Thanks for the ongoing feedback. I will,post some pics tomorrow, assuming I can figure out how to do that. My basic question is: given that a contact (or two with my newer column switch) is making contact with the back of the steering wheel brass hub, that hub continues on the front side if the form of a ring. I don't see how moving the horn button down to contact that ring changes any sort of circuit. (Because the ring is already energized all around its circumference -- because it is connected with the back side, right?). So I don't see what the horn button contact is doing. If depressing the horn button somehow brought the contact(s) on the switch column into contact with the brass plate on the back, I could see that. But I see no way that depressing the horn button changes anything physically on the back side. My apologies if this description is confusing...

Thanks!

[blazingspider]

Been awhile since I've taken my steering wheel off but from what I remember on my 77 both contacts for the horn DO NOT ride on the brass ring. One does and the other one rides further inboard on the metal hub.

[Kwlittle]

Well, I'm making some progress but not there yet. Thanks to BlazingSpider's info, I have sorted out my confusion about how the completed circuit works when the horn button is down. I couldn't see how having the button down on the brass ring completed any sort of circuit. The hot contact on the column switch is making contact with the ring, okay, but how does putting the button down on that ring then complete a circuit. Then I realized, doh, that the SPRING is in contact with the hot ring/ button plate AND the hub of the steering wheel itself, which is in contact with (thanks BlazingSpider) the ground contact on the column switch. So the horn button's spring was the missing piece in my confused head.

Where I am now is that I have continuity between the hot contact on the column switch and the black wire to the horn relay switch. (With the steering wheel removed.) My wiring diagram confirms that's how it should be. However, when I put the steering wheel down on the shaft -- even cranking it down -- there is no contact between the steering column contact and the brass plate on back of the steering wheel. I can't get continuity there. The newer column switch that I installed (this is one from an unknown year to me but does have an additional green wire in addition to the two multi-wire connectors) has a rotating black plastic disk surrounding the contacts that is apparently bumping into stuff on the back of the wheel preventing contact. I don't think it's even close, i.e. bending the contacts up more doesn't help. There is no such rotating disk in the old, original column switch that did allow contact. I suppose I could simply cut it out of there to allow closer proximity but hate to do that, yet. (I can see why it's desirable for it to be there.)

Question: do the newer Spiders (that might have come with this type of switch with this disk) have different steering wheels than the older ones like my '69? Maybe I just have some fundamental incompatibility here? Maybe I could solder extensions onto the two column switch contacts but that doesn't seem very elegant. Don't really want to buy a newer steering wheel either. (This is a "restoration"!)

Ideas? Many thanks again for y'all's help so far...

[blazingspider]

Have your fixed you horn problem yet? If not, it would be helpful if you could post some pics of the backside of the steering wheel and the hub assembly with the contacts.

Also, here's an excerpt from an old post on another forum about the subject that you might find helpful.

"My second problem was with the way that I had installed the column switches. I had installed the assembly too low on the column which did not allow the flange to come into contact with the bottom of the steering wheel. I moved the switches up on the column (toward the driver) until the top was flush with where the teeth for the steering wheel begin. Worked great."

[Kwlittle]

Thanks again, BlazingSpider

I've "fixed it" in the sense that I now know how things are supposed to work (thanks to you), and why they don't. Why they don't is because my column switch and steering wheel hub are incompatible. On the back of my hub -- off my '69 -- are some flanges that stick out preventing contact. (I tried securing the wheel,to the steering shaft and then sliding the column switch up as far as it would go, but still no continuity). I googled "fiat 124 spider steering wheel" and in the "images" thing that pops up (incredibly useful, Google) was the back side of a steering wheel from Midwest-Bayless -- advertised as for 1973-1978-- that did not have these flanges and also had a clear inner and outer ring for contacting the ground and hot contacts, respectively. So, there are obviously differences in steering wheel hubs. I'm still assembling my car and cost is an object, so I'll leave a steering wheel replacement for stage 2, after I get the engine and transmission back in and the thing actually running. I figure you don't really need a horn until it can move under its own power!

Thanks everyone for your help and interest.

[blazingspider]

"I figure you don't really need a horn until it can move under its own power!" +1 on that!!

[vandor]

> On the back of my hub -- off my '69 -- are some flanges that stick out preventing contact.

Likely part of the turn signal cancelling mechanism.

>was the back side of a steering wheel .... had a clear inner and outer ring for contacting the ground and hot contacts, respectively

Sorry, you are seeing something that is not there. Fiat never had such a wheel, there was only one ring on the back. It is the column switch that is not wired properly.

[Kwlittle]

Look at the back of the steering hubs on these two links. That's all i know. they certainly look different to me.

http://www.midwest-bayless.com/p-15834- ... 968-72-u85.

http://www.midwest-bayless.com/p-15833- ... 3-u85.aspx

[blazingspider]

Your first link didn't work for me. The second link looks like the steering wheel from my 77.

Take a look at the back side of this steering wheel for sale on ebay. Note how he says it was from a 76 but may have also been used on the 850s. This is the steering wheel you have right?

http://www.ebay.com/itm/FIAT-124-SPIDER ... 2362b6aae4