Could BOTH my horns be bad?

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ricomondo

ricomondo

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71 Demon - ALL new wiring; under dash, column, engine etc and NOS horn relay.

Horns had been working - Prestolite pair that I had the powder coater PAINT and not powder coat due to the heat.

Horns stopped working, checked fuses - all good.

Standard base steering wheel - push the button and you can hear the relay "click".
Took horn pad off and took the column connector off the steering wheel switch and grounded to the center nut, same thing relay just clicks.

Bought new relay - same thing just clicks.

Then ran piece of 14GA wire from the + post and touched it at the post and the terminal on each horn, nada.
Removed the horns from the brackets and laid them one at a time over the - battery post and touched the wire from the + post to the horn terminal and nada.

I did screw in/unscrew the adjuster screw on the front of the horn and same thing.

Could BOTH horns have gone bad? or am I missing something?

I did dig through various horn posts here on the forum before posting.

TIA
 
Did you clean off the paint where it bolts to the car? It relies on the mounting as a ground.
If in doubt, run a wire to the positive battery and touch it to the contact on the horn.
 
I would check with a test light at the plug and have someone hit the horn and see if you are getting power. If you are it's the horns. Putting voltage to the horns should have made them sound. Double check the ground too.
 
ricomondo said:
Then ran piece of 14GA wire from the + post and touched it at the post and the terminal on each horn, nada.
Removed the horns from the brackets and laid them one at a time over the - battery post and touched the wire from the + post to the horn terminal and nada.
Click to expand...


Effectively, with this kind of tests, it seems that both horns are toast :(
With the bracket touching the - terminal, and a wire from the + post on the horn terminal, it has to sound. No alternative.
 
One more thing to try: the horns often get "stuck" due to lack of use. To unstick it, lay it on a block of wood and give it a good whack right on the center bolt (NOT the bell) with a nonmetallic hammer. They can often be jarred loose this way.
 
340wedge said:
I would check with a test light at the plug and have someone hit the horn and see if you are getting power. If you are it's the horns. Putting voltage to the horns should have made them sound. Double check the ground too.
Click to expand...
@340wedge - ok, will check at the plug and report back. When you say check the ground? Which ground?
At the bracket on the rad support? The brackets were previosuly powder coated, so perhaps I should take some of the paint off the bracket where it meets the rad support? But will check the two plugs on the harness first.
 
Ok, hooked test light to each of the plugs and had my son press the horn button, each horn press resulted in the test light illuminating. So it appears power is getting to the plugs, so must be grounding or the horns are bad, but as I stated I ran a power wire to each horn and nada?
 
I have usually found these issues to be a lack of a good ground. The horn MUST have a good ground from the bracket to ground. Was the bracket removed and painted? If so, could the continuity from the bracket to inside the horn be coated with paint?

It sounds like you are testing all the right things. Just make darn sure the horn has a good ground as it would be too much if a coincidence for BOTH to quit at the same time. (And like @340wedge noted, be sure to see if 12v is being applied at the horn spade when you hit the horn button.)
 
Demonx2 said:
I have usually found these issues to be a lack of a good ground. The horn MUST have a good ground from the bracket to ground. Was the bracket removed and painted? If so, could the continuity from the bracket to inside the horn be coated with paint?

It sounds like you are testing all the right things. Just make darn sure the horn has a good ground as it would be too much if a coincidence for BOTH to quit at the same time. (And like @340wedge noted, be sure to see if 12v is being applied at the horn spade when you hit the horn button.)
Click to expand...
@Demonx2 - well I am getting power at both plugs when the horn button is pressed - test light illuminated with each horn press. I'm just confused as I ran a wire from the battery to each horn terminal and nada.
 
Here's a horn mounting bolt. You can see the teeth designed to dig into the mounting bracket and ground through the bolt threads. Do you have these?
1690417026180.png
 
To sum up others

Make CERTAIN you have a good ground, the bracket / mounting hole is usually best as the bolt as scraped it up a bit, but you can use screwdriver, scraper, whatever to do so. use a jumper cable , etc on the bracket to the battery post

Mark the adjuster so you know it's position (you can tune them) and don't be afraid to twist it back and forth. Often the threads of the adjuster are rusty, and THAT is what grounds the contacts inside. The contacts are often burned and twisting the adjust often causes it to conduct and you can then work the adjuster back and forth from there

Make sure you are using a good heavy wire, no14 is good. You can connect to the battery with say, vise grips and then touch the wire to the horn terminal by hand, but be careful you don't get burned. That contact can be warm, and the action of the horn can shock you.

If you get the horns working "on the battery" and they still won't operate, check the horns for voltage right at the horns. Access the horn wire (black) at the column connector. Stick a jumper wire in there and ground it to lock the relay energized. Then take a multimeter and leaving the horns connected, probe the horn connectors and look for "should be" nearly same as battery, AKA about 12V

To check for horn grounding with relay locked energized, touch your multimeter probe (other probe grounded) to the horn metal. If you read ANY voltage there, the horn is not grounded
 
My money is the powder coat on the brackets at the horn to bracket interface is making the insulation.
And the paint elseware is contributing.
 
As @67Dart273 says, be sure you are getting a good 12v, not just lighting the test light. And FWIW, i have fought a bad ground issue where the bolt threads in the rad support would sometimes be ground, and sometimes not. So I actually ran a separate ground wire from under the washer!

Keep at it as these other better experts are coaching. You WILL find it and fix it. OR, you'll just have to give the car to me and I'll be forced to change my handle to Demonx3!!
 
ricomondo said:
@Demonx2 - well I am getting power at both plugs when the horn button is pressed - test light illuminated with each horn press. I'm just confused as I ran a wire from the battery to each horn terminal and nada.
Click to expand...
Then do the opposite. You're verified power. Now verify ground. Put the test light clamp on the positive battery terminal and probe the horns, brackets and wherever they mount with the test light to check for ground. I'm like the others, Either paint or powder coating is stopping the ground signal.
 
RustyRatRod said:
Then do the opposite. You're verified power. Now verify ground. Put the test light clamp on the positive battery terminal and probe the horns, brackets and wherever they mount with the test light to check for ground. I'm like the others, Either paint or powder coating is stopping the ground signal.
Click to expand...
Thank you, will check them with this method tmrw and report back.
 
I've had limited success supplying power, and repeatedly tapping with a hammer handle.
They may beep a coupla times, with continued tapping, some become serviceable, some not .
Good luck
 
Last edited:
If either orange circle has too much paint/powder coating there will be a bad/no ground situation.

AND anywhere on the powder coated bracket will be insulated (Powder coating is melted plastic like wire insulation)

so touching the bracket to the negative battery terminal is like touching the insulation of a wire to the terminal



1690424088050.png
 
What usually happens is when media blasted without installing a sponge in the opening the media gets in the horn and works its way to the center of the snail. Take them off an tap them on something while hooked to a battery. Turn the adjuster screw back and forth until the start working. Tap them on a hard surface and turn them in the direction to get the dirt out of the snail style funnel. This worked for me a couple of times. you can adjust the tone while doing this.
 
Every tool box needs a Power Probe 3.

With the horn on the car you can feed power or ground right to the horn and instantly know if the horn is good.
 
67Dart273 said:
To sum up others

Make CERTAIN you have a good ground, the bracket / mounting hole is usually best as the bolt as scraped it up a bit, but you can use screwdriver, scraper, whatever to do so. use a jumper cable , etc on the bracket to the battery post

Mark the adjuster so you know it's position (you can tune them) and don't be afraid to twist it back and forth. Often the threads of the adjuster are rusty, and THAT is what grounds the contacts inside. The contacts are often burned and twisting the adjust often causes it to conduct and you can then work the adjuster back and forth from there

Make sure you are using a good heavy wire, no14 is good. You can connect to the battery with say, vise grips and then touch the wire to the horn terminal by hand, but be careful you don't get burned. That contact can be warm, and the action of the horn can shock you.

If you get the horns working "on the battery" and they still won't operate, check the horns for voltage right at the horns. Access the horn wire (black) at the column connector. Stick a jumper wire in there and ground it to lock the relay energized. Then take a multimeter and leaving the horns connected, probe the horn connectors and look for "should be" nearly same as battery, AKA about 12V

To check for horn grounding with relay locked energized, touch your multimeter probe (other probe grounded) to the horn metal. If you read ANY voltage there, the horn is not grounded
Click to expand...
THIS !!

I bought a set of Horns from Tony's Parts (GraveYard Car fame) and although they were in new condition, they didn't work. I played with the adjuster a bit and voila!! Horns worked perfect and no issues 5 years later.
 
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