Hey all,
I must be missing something here.. The horn on my '65 Satellite stopped working. Is there anything unusual about the way these are wired? Power goes to the horn ring switch, then out to the relay, which triggers higher amp voltage to the horns. My horn ring at the steering wheel isn't the best, but I have always been able to press it hard enough to activate the horn. Now all I get is the "Click" of the relay..

So far ..

I've checked power and continuity in the wiring to the relay on the firewall. 12V comes in on the power side The relay clicks when I press the horn ring.
I've checked continuity across the relay terminals and the relay opens and closes the circuit properly when I press the horn ring hard enough and it makes the click. So the relay must be OK?
I've checked wiring from the relay to the horns, and they show continuity.
I've jumped power directly from the battery to the horns, and they sound loud. The Ground must be OK..

I'll try it all over again, because this should be a really simple circuit..

.. am I missing something?

Thanks for any ideas..
- Art

Have you checked for voltage at the horns when the relay closes? Just because you hear it click doesn’t mean it’s working properly

I'm under the impression the horn button provides the ground for the horn relay .
I would try grounding the horns with a jumper wire to the block or some other good ground source to make sure that poor grounding on the horns isn't causing your issues
Direct current, low voltage like our cars operate on need, excellent grounds as the current flows from the negative side of the battery back to the positive terminal, if the grounds are not good it won't flow well

I don't know if you missed anything, but I would be isolating parts and working backwards instead of using the system to check the system if that makes sense.

so your first check is the horn works.

now back up to the relay.
or rather wiring from the relay.
use the jumper to supply power to the horn from the relay wire to the horn. Make sure that is still good.
if the horn sounds back up to the other side of the relay power supply.
to do that though you might unplug the horn ring ground and wire up a wire to ground the relay from where the horn ring would have done it and see if the horn sounds.
if it does you back up to the bulkhead connector and see if you can ground it from the outside and then the inside, etc..

I have had an issue with the horn not working in my '67 Fastback. I checked everything under the hood, and traced the problem all the way back to the bulkhead connector. On the inside of the firewall, under the dash, the wire for the horn had pushed out of the bulkhead connector and was not making good contact. they are just spade connectors, and can easily be loose and get pushed off their retention clip. If you go nuts under the hood to no avail, check your bulkhead under the dash for that wire. On my car, it is the wire that is at the top right hand side(from the inside car perspective). (Purple i think?)

On the 70 and up stuff that is definitely the case. I am pretty sure it was the same in 65. The horn operating as a ground button is the reason for the relay. The relay field is fed positive current all the time. The ground side of the field is attached to the horn button. When you press the horn the circuit is completed and the relay closes feeding positive to the horn.

Many times the horn issues are caused by a bad ground to the steering column.

I would start with a test light and check work my way back from the horns. If no current to the horns then follow it back to the bulkhead. Check for voltage on both sides when the horn is pressed. Lastly check for voltage coming out of the relay. IT could be bad contacts allowing continuity but not enough current to operate the horns.

Since these relays are pretty durable and not used often I am leaning towards what Swinger said, a bad bulkhead connection.

If the relay is clicking then it sounds like your horn button is doing it's thing and the problem is the relay ?

You can eliminate the wiring to the steering column and the horn button by grounding the terminal that comes from the steering column , as noted by another person. If the horn sounds the problem is between the relay and the button , if it doesn't sound the problem is the relay since you say the horns sound. Also check the ground between the relay body and the body.

My Challenger sat in my garage for 27 years. When I finally had the means and time to restore it, the horn didn't work. Eventually, I found that the copper ring in the column wasn't making continuity. I took some fine emory cloth and dressed the surface and that fixed it!

Thanks guys, I appreciate the input - I'll check all connections and the copper steering wheel ring.. and check each piece of advice.

I *do* get 12V at the horns when I connect a volt meter to the wire coming from the relay and ground - but I wonder if it could be a matter of amps? What I mean is, could there be 12V but still be a poor connection that limits the amperage?.. enough amps to engage the relay, but not enough amps to "drive" the horns? I'm not smelling anything melting.. .

Anyway - you've all given me a good amount of things to check, so when the rain stops in 3-4 days and I can get it back in the garage, I'll keep looking.

Best,
- Art

1. you earlier stated that the relay Clicks when the horn button/ ring is depressed. That says the ground signal from the horn switch is making it to the relay And that the coil in the relay also has 12V to it's other side
When the ground is applied the coil windings create a magnetic field in the iron core (rod) they are wrapped around

2. This magnetic field Pulls the points closed sending 12 V to the horns. This V / I (current) goes through the horn windings to body ground.

3. This and another set of point inside the horn cause a diapraghm within th ehorn to osciallate creating the sound waves that make the noise.

Batter explanation here HOW A HORN WORKS

You are correct in asking the bolded part of your post above. The power source (wiring) to the relay may be enough to actuate the relay but not supply enough Current through the relay points to the horns.

it may also be the points within the relay are oxidized or burnt

It may also be a bad body ground at the horns or the points within the horns themselves.
Isn't electricity FUN???

I would suggest taking a 16-14 GA wire directly from the battery post to the horn terminal. No spark when touching the terminal indicates a bad ground on the horn, open windings in the horn itself, or burnt oxidized points within the horn.

This will tell you if the horns or relay are at fault.

I have sometimes had luck reviving a horn by adjusting the tone screw.
3 other culprits are
Is if the horns have gotten wet and corrode inside
Have been sandblasted filling the insides partially with media.
Or full of overspray from painting the horns and or car with the hotrns in place
Again sometimes they can be flushed out, and others not
hope this helped a bit