Learn Me: Horns. No, Seriously.

So, my stupid 1997 Dodge Dakota needs to pass safety inspection, and part of that is having a working horn. About a month ago, it stopped working out of the blue, and I figured it was the horn relay, so I replaced it. Nope. When you depress the horn button, you can hear it clicking.

Then, I busted out the multimeter, and hooked it up to see what's going on. The horn circuit is simple: switched power and ground. I put the positive on the switched power clip and the ground to the chassis. And it's getting voltage.

Now here's where it gets tricky: this Dakota has one low-tone horn. I always thought it was the factory horn, and it very well may be, but every other 1997-2004 Dakota at the local junkyards has TWO horns: a low and a high, and with different wiring. The low and high both have a green and red wire (the switched power) and a black ground. My Dakota also has one green and red wire and TWO grounds that connect together in a loop that attaches to the chassis. I even grabbed one of these two-tone setups from the junkyard and tried wiring it up. Nope, nothing.

I'm at my wit's end. Only thing I haven't tried is testing the horn straight up off of the battery hot to see if they sound. Am I missing something here, or should this thing just work?

If the relay is working the horn should just work. Have you checked the power input and output at the relay? It may be clicking but not delivering power.

Horns are basically a diaphragm with a magnet that acts like a giant version of a buzzer. They get corroded or packed with dirt unless it got stuck on for a day and overheated. If the winding is toast - you just need another one. But, sometimes all you need to do is blast it out with a garden hose, dry it and shoot some WD-40 in there if it's been drinking road grime and is all plugged up.

DeadSkunk wrote: If the relay is working the horn should just work. Have you checked the power input and output at the relay? It may be clicking but not delivering power.

It's getting voltage at the horn wiring when the horn button is depressed, so I assume the relay is doing it's job.

If the horn has voltage on one side, a ground on the other (check its voltage relative to the negative terminal of the battery), and is not sounding, the problem's with the horn.

I recommend the old Cadillac four-tone horns. They sound like a locomotive.

chaparral wrote: If the horn has voltage on one side, a ground on the other (check its voltage relative to the negative terminal of the battery), and is not sounding, the problem's with the horn. I recommend the old Cadillac four-tone horns. They sound like a locomotive.

I may have left something out.

So, the horn itself has a positive terminal on it, and nothing else. The ground wires come off of the harness and go to the chassis. The horn only has provisions for the positive terminal, and it's always been that way. It was always grounded to the chassis, too.

The new (to me) dual horns have positive AND negative on each horn. Only thing I have not tried is clipping the negatives from the harness and connecting directly to the new horns.

Tony Sestito wrote:

chaparral wrote: If the horn has voltage on one side, a ground on the other (check its voltage relative to the negative terminal of the battery), and is not sounding, the problem's with the horn. I recommend the old Cadillac four-tone horns. They sound like a locomotive.

I may have left something out. So, the horn itself has a positive terminal on it, and nothing else. The ground wires come off of the harness and go to the chassis. The horn only has provisions for the positive terminal, and it's always been that way. It was always grounded to the chassis, too. The new (to me) dual horns have positive AND negative on each horn. Only thing I have not tried is clipping the negatives from the harness and connecting directly to the new horns.

I'd give that a shot. There's always a chance the negative on the new horns is isolated from the horn bracket.

If that doesn't work, I agree with above comments - test it directly against the battery.

chaparral wrote: If the horn has voltage on one side, a ground on the other (check its voltage relative to the negative terminal of the battery), and is not sounding, the problem's with the horn. I recommend the old Cadillac four-tone horns. They sound like a locomotive.

You can scrounge the four tones off separate early 90's-earlier GM cars. I have a set of A, C, D, and F from various Buicks, Chevys and Pontiacs.

Have you checked the voltage at the horn under a load? Meaning check for voltage at the positive terminal on the horn with everything connected.

Just be glad it's not a can-bus horn. I just learned that those were a thing recently....I know which part of the machine the Germans designed.

Musical horn with "Dixie" on it /thread.

I ran a whole new switch for mine. The horn itself was rusted apart, plus the cops cut the wires when they cut the siren.

New horn, on its own switch and relay, with the button where it fit.

Not sure how particular your inspection people are, mine gave me some crap for it being not the regular horn location, but it works so it passed.

Test it off a battery before you go creating wiring circuits to fix a problem you may or may not have.

mazdeuce wrote: Test it off a battery before you go creating wiring circuits to fix a problem you may or may not have.

Good point, and since the relay is clicking, it's very unlikely a problem on the switch side. Please note that a clicking relay is not automatically a good relay. The clicking from the tips moving only means the switch, coil and armature are working.

1 wire horns ground through the bracket, 2 wire horns ground through the second terminal.

Those two ground wires likely have nothing to do with the horns. Cut them at your own peril.

Hook up the green wire, add grounds. Its also possible the ground path on the original horn through the mount bracket is corroded and non conductive.

Use your jumper cables to test the old horn and new one(s) directly to the battery. Once you figure out how and if they work wire truck accordingly.

As others have recommended try it on a battery before installing, If the battery doesn't get it to beep then it is NG. If it works, take the new horns Ground (-) leads, and land them somewhere you think has a good reference to the frame, then connect the Positive (+) wires and the horn button should beep the horn. Or get an Air Horn, those are great for Boston drivers.