Power to horn button but none to horn

[YNOTBOB2007]

I have a 69 with a stock horn/button (I believe). Under the horn button are 2 larger wires....one yellow and one blue with yellow stripe.There is full battery voltage going to the 2 contacts under the horn button. But when I jumper the 2 contacts together, no horn. I checked the horn itself and no power is getting to it (pre relay horn....69). So something is happening from the contact to the horn. Any ideas? Where does the horn ground? Thanks.

 

[Oldtimer]

Unless I have the colors reversed:
Yellow (YE) wire should be 12v from battery.
Horn button should connect YE contact to the BL/YE contact.
Blue/Yellow (BL/YE) stripe wire should should feed to horn.
Horn ground is short wire to screw on core support (headlight ground wire may share screw)

Check the plugs where harness comes out of bottom of column.

 

[Broncobowsher]

I would inspect the column to body harness. The turn signal switch (with brushes for the horn) has likely been replaced a time or two and the wiring at that junction may not have been done right.

 

[YNOTBOB2007]

Unless I have the colors reversed:
Yellow (YE) wire should be 12v from battery.
Horn button should connect YE contact to the BL/YE contact.
Blue/Yellow (BL/YE) stripe wire should should feed to horn.
Horn ground is short wire to screw on core support (headlight ground wire may share screw)

Thanks...I'm not seeing the ground wire. Is it coming from the horn itself or the steering wheel? I was assuming the horn grounded itself on the body but maybe I'm wrong. The horn was working....but last I used it was 3 years ago...maybe some corossion somewhere?

 

[Oldtimer]

Ground wire comes from horn.
Some horns did not have a ground wire. They used the mounting bolt for ground.

The blue/yellow wire should run down column, go thru a connector at base of colum, and then out to the horn.
As broncobowsher said check the wires at the connectors, they may have been "re-arranged" in the last 53 years.

 

[YNOTBOB2007]

yes...mine is grounded from the mounting bolt. I've cleaned it up but no change. There seems to be a disconnect from the yellow wire to the blue/yellow at the wheel...or the blue/yellow is shorted somewhere from the wheel to the horn.

 

[Oldtimer]

If you jumper the contacts together, there should be 12v on blue/yellow wire all the way to the horn. Start checking harness for broken wire.

 

[YNOTBOB2007]

If you jumper the contacts together, there should be 12v on blue/yellow wire all the way to the horn. start checking harness for broken wire.

yep...but there's not...that's the problem. I'll look for the blue/yellow coming out of the firewall.....all my wires look black lol

 

[Broncobowsher]

That is where I say look at where the column wiring mates to the body wiring. It is a junction point that gets messed with a LOT, as in every time the turn signal switch gets replaced. For me, that is every 10-20 years on old Fords.

 

[DirtDonk]

First issue is that you should not see 12 V on both of those contacts. In your first post, you said you measured full voltage at both, but it should only be on one.
So that seems amiss right off the bat.

You can test the horn by running a power wire directly to it. If it honks at that point, then you know that the horn and its grounding point are still good.
You could even do that at the firewall connectors, and at the steering column connectors to keep tracing things and narrowing down the prospects.
Since it worked before and you’re seeing 12 V on both, seems to me there’s a good chance that some of the wires have become frayed and shorted inside the steering column.
But that would be the last thing I would hope for and try to fix.
Check the easy stuff first.

After you get it all sorted out, I would convert the system over to a relay without a doubt. It’s hands-down how it should’ve been done originally.
It reduces the wear and tear on the contact points in the horn button and usually makes the horn louder.
It’s also very easy to do so.
Let us know when you get that sorted out and it’s an easy walk-through with a relay.

 

[Madgyver]

I don't have a washer pump so I used that circuit for my Stabel horn through a relay. Press the wiper button for horn blast. Turn signal circuit and horn circuit in steering column is a pain to get working properly.

 

[YNOTBOB2007]

First issue is that you should not see 12 V on both of those contacts. In your first post, you said you measured full voltage at both, but it should only be on one.
So that seems amiss right off the bat.

You can test the horn by running a power wire directly to it. If it honks at that point, then you know that the horn and its grounding point are still good.
You could even do that at the firewall connectors, and at the steering column connectors to keep tracing things and narrowing down the prospects.
Since it worked before and you’re seeing 12 V on both, seems to me there’s a good chance that some of the wires have become frayed and shorted inside the steering column.
But that would be the last thing I would hope for and try to fix.
Check the easy stuff first.

After you get it all sorted out, I would convert the system over to a relay without a doubt. It’s hands-down how it should’ve been done originally.
It reduces the wear and tear on the contact points in the horn button and usually makes the horn louder.
It’s also very easy to do so.
Let us know when you get that sorted out and it’s an easy walk-through with a relay.

thanks....yes, unfortunately I have power to both contacts. The horn works when wired directly to the battery. Thanks for the tip. Blinkers work fine. This is the original wheel. I do remember years ago getting the horn chirping when turining corners as I've read about on here. I opened things up and corrected the short back then. Since then everything has worked fine. When you say firewall connectors.....there are 2 rubber "boots" with about 6 wires in each coming out of the firewall just above the drivers side valve cover....looks to be factory. I think the large black wire is the fusible link. Nothng is spliced there that I can see...unless the boot diconnects with male/female connectors? Is that where I can test (assuming the boot is two piece?). And in the column behind the horn button and plastic bezel are the wires....one yellow and one blue/yellow stripe. Nothing looks freyed....maybe I should remove their connectors and plastic turn signal plate and look deeper? Is there anything further down the column (that is accessed from under the steering column from insude the truck?). Lots of questions....I appreciate everyone's replies.

 

[Oldtimer]

The wires from turn signal switch & horn exit the column just past the lower edge of the dash. On my 68 the wires are terminated into 2 connectors, a 2 contact, and a 6 (or 8) contact connector. I would de-mate those connectors and check the yellow & blue/yellow wires on the vehicle side for 12v.

 

[Oldtimer]

It is a 6 contact plug with 8 wires in it. Blue/ yellow wire is in near right corner, yellow wire is in back left corner.
The wires in the mating connector get removed every time turnsignal switch is replaced. Experience says your Bronco is on it 3rd or 4th switch, and may have been miswired more then once.

 

[YNOTBOB2007]

OK...I found the wires exiting the column....mine has different conectors (1969)....one blue plastic onnector per wire. The connectors do not separate as far as I can tell. All look good. I can follow the blue/yellow stripe wire going from the connector into the back of the fuse box. My user manual (original) shows the horn wiring is on the same circuit as the stop lights, taillights and license plate light...which is a 15 amp circuit breaker "intergral with the lighting switch". I am assuming "integral to the lighting switch" means there is no actual glass fuse? And even if there is one and it's bad, the lights wouldn't work. Are you getting battery voltage to both horn contacts or just one?

 

[Oldtimer]

Only one wire is 12v. The other wire goes all the way to the horn, behind left headlight.
I am out of town till next week, so I can't verify which wire is the hot wire, but my rusty memory says it is the yellow wire.

Can you post a picture of your connectors?

 

[YNOTBOB2007]

I think you are right...yellow should be hot. I don't know how to post pics...I have some but don't know how to make a link. So as DirtDonk mentioned...right out the gate something is off since I have power to both contacts. Odd since I haven't worked on this horn for 10 years. I will say that when it was working, I had to press hard on the BOTTOM of the button to make contact with the internal contacts. But jumping them with alligator clips is not sounding the horn now.

 

[YNOTBOB2007]

Also to be clear, when I say I have power on both contacts, these are the 2 small contacts under the horn ring/plastic bezel that are connected to small plastic tabs...not the 2 longer contacts (1/2" or so long) behind the plate in the column.

 

[Oldtimer]

I am talking about the two spring loaded posts that rub against the bottom of the steering wheel. They are to the right side of the steering column.

 

[YNOTBOB2007]

I am talking about the two spring loaded posts that rub against the bottom of the steering wheel. They are to the right side of the steering column.

Oh wow...that could be why my troubleshooting isn't working....I've been jumping the ones just under the button...not the two on the right that rub on the bottom of the wheel. So if I jump those, I should get the horn?