Technical ** fixed**Getting shocked when hitting the horn. 41 Ford

I did suspect something like that. That is why I thought the relay was the problem.

 

If there is a relay between the horn and the steering wheel it's the relay that provides the spikes. Same principle, that's a coil too.

 

That is what you should read on a system that provides a ground to the relay.

 

You are reading the open circuit voltage of the relay coil. It's not a problem, it is normal.

 

There's probably a lot of things going on here. OEM horn relays typically have only three connections; power in, power to the horns and the ground side of the relay coil. The relay coil power is internally common to power in. If you have an OEM column and steering box, the ground path is through the shaft/steering box as the upper shaft bushing is a metal bushing enclosed in a rubber surround, so no path there. So I'll ask a few questions...

One, do you get the shock between the horn ring and the garnish when the ring isn't being depressed? I suspect not, in spite of 12V being present between them.

Two, do you get shocked when depressing the horn ring with the horns themselves disconnected but the control part is still active?

Three, what type of relay is used? If it's a 4 or 5 pin typical Bosch style, I'll bet that the 12V coil power is connected to the main horn circuit coming in, emulating the OEM circuitry.

This is obviously a ground path issue. Electricity always takes the path of least resistance; in this case it's the guy pressing the ****on with his arm partially out the window. And my comment about hot rodders not liking bare metal applies. The OEMs weren't exactly liberal about paint in less-seen areas, with zero paint also being common. A couple of mils of paint is a more than adequate insulator with only 12V. Powdercoat is much worse.

If your answer to the questions are no, no, and yes, the easy solution will be to separate the relay coil power from the horn circuit and feed it from someplace else.

 

A loose, rusty, or broken ground connection stops power from flowing back to the battery. When that return path fails, electricity tries to find another way out, causing strange, unrelated components to act up at the same time. When is the last time anyone on this thread performed any sort of regular maintenance on their grounds? Nevermind, I already know the answer.

 

It's not just those. Wired ground connections are generally just short jumpers, few people think about all the bolted connections that are also important for electrical continuity. Put paint between those and your grounds are now degraded...

 

I had a similar problem with a push in factory type starter ****on in a 40 ford my wife thought it was hilarious me not so much but it makes me laugh now thinking about it. it grounded through my elbow soldered a wire to the ****on and screwed it to the dash never happened again

 

I would just keep it shocking people and call it a theft deterrent. Tell them the shock get progressively worse until you return the car back to the owner.

 

To answer a couple questions you can touch it with both hands and nothing happens, as far as one hand on ground and one hand alone ring. When you push the horn ring it shocks you. Not when you let off. It has a 4 pin bosch relay now but had a regular three wire horn relay first and I thought I'd swap it and see what it does with no change. I'm pretty sure that I disconnected the horn and it still shocks you

 

Check the wire under the horn ring to make sure it's not "grounding out" when you depress the horn ring. The horn ring should be insulated from all other metal.

 

When you depress the horn ring the horn ring itself is what grounds to the actual wheel to make the contact

 

I started seeing this problem in the 'it's when the billitt craze was going strong. Billitt steering wheels would shock when depressing the horn ****on. Figured out it was the relay coil unloading. Went to more convential grounded base relays to solve the problem.

 

When you say conventional grounded base relays do you mean just the regular three prong Factory units?had a oem 3 prong unit and it did the same

 

I like where this is going. The relay case is grounded.

 

Yes, like was used on mid '50's GM products. Usually mounted on the inner fender well. Anyway, that's what worked for me.

 

that's what the car had when it came in and still shocked

 

Well, after some research I think I'm closing in on the issue...

First, the relay isn't producing the voltage spike. When the ring is pressed, power is supplied to the relay and its contacts close and stay closed as long as the ring is pressed; the horn(s) make noise. Coils don't produce a spike until power is removed, which is how an ignition coil works. However, the horn(s) operates by energizing a coil to move the diaphram, once it's moved enough a set of contacts open, the diaphram returns to its off state and air is moved. Repeat multiple times (hundreds or more) per second and noise is produced. And as these are much higher current compared to the relay coil, a sizable voltage spike is produced. Theoretically, disconnecting power to the horns only at the relay should eliminate that spike. I would double check that. I'll note that this seems to be a common issue, with multiple posts various places including here... 1947 ford horn ****on | The H.A.M.B.

I tried in vain to find a detailed breakdown of the horn ring ***embly but did find a few vague references to 'felt washers' and 'rubber insulators' in its ***embly. I can say that when looking at some newer Ford horn ring ***emblies, the chrome ring is electrically isolated from the metal part that makes the actual circuit contact, with the newer versions generally using plastic washers electrically separating the two pieces. This would fix the issue if those parts were missing, so this would bear a thorough looking at. It would seem to indicate that the factory had this same problem, and this was their solution.

Ultimately, it's still a grounding path issue, but given that the path goes down the shaft, through the steering box bearings/gears (all running in insulating grease), then the box housing, into the frame and from there somehow back to the negative battery terminal (how well is everything bonded?), the possibility of a high-resistance path seems rather high. Adequate for the low-current relay coil, but not good enough for the spike from the horn(s).

 

The horn wire is connected directly to the actual horn ring. And that's how it is grounded to the steering wheel itself. there are no isolators and if there were it would not work.

 

OK, but are you sure all parts are there? Got a pic of the business side of the ring?

 

I don't see anything that could be missing. Maybe they're supposed to be a isolator between the tensioner spring and the actual wheel?

 

Got a pic of the backside?

 

here is a picture from the internet of the back side and you can see where the actual wire attaches into the screw hole boss

 

Well, those fiber washers are there for a reason and it appears to me that if the part that is attached to ring were isolated from the ring (and no direct electrical connection to the chrome ring) that would fix the issue.

 

I'll have to look at that tomorrow when I get into work but I'm in town now and I'll pick up some little plastic fiber washers see if I can make something work

 

Here is a mention of a rubber 'donut' used. They also mention that the wire that goes down the shaft is a special 'high resistance' wire to reduce 'static shock'.

https://www.google.com/search?q=194...uAe-BsIHBTAuNC41yAcbgAgB&sclient=gws-wiz-serp

They have a link to the Early Ford V8 club, but unfortunately there are no pics showing...

 

Hmmm.... the rubber insulator is cracked in a few spots and I tried to order one Friday from cw moss Ford parts but they wouldn't answer the phone so I've got to order a couple things tomorrow anyways then we'll get another one of them. I'd like to know what that that resistance wire is I've also read a couple things about it

 

Yeah, the wire caught my eye too.

And thinking a bit more, I wonder if connecting a capacitor to the power connection to the horns wouldn't reduce the spikes also. But if you can get the chrome ring isolated from the circuit, that should fix the problem.

 

I don't think I can as the Chrome ring is what grounds to the steering wheel and that's what completes the circuit

 

It's not the chrome ring that grounds, it's the bits that are screwed to the ring that are supposed to be doing that. That's why those fiber washers are there.