Grounding And A Horn

Hey guys,

So I’ve tried almost everything I can think of. I’ve got a modern style 12V Hella horn I've been trying to get installed for the first time on my 12V M38. I think I need a better grounding location for it.

The horn works great connected straight to the battery (scared myself good on that one).
The horn button works.
Re wired everything too.
Even tried just connecting the wires at the dash without the button.
Fuse on the block is fine. The block sends power to other components straight from the battery. (Unswitched block).

But when I attempt to sound the horn, it just goes “squeek” and makes kind of a click chirp sound. Nothing. I’ve got around with my good multimeter too, with the positive on the positive battery terminal, and touching my other grounding locations and bolt heads around the engine and firewall... and I’m getting no DC current flow. I’ve touched the negative lead to all sorts of places and no current flows from the battery.

Do you have any ideas? Am I doing something wrong? I feel like my Jeep won’t ground maybe, is that possible? Do horns have to be grounded to the battery neg?

Thanks.

 

The horn is temporarily mounted to the firewall. That shouldn’t matter... right?

My Jeep has a 4 prong fuse block that is powered straight off the battery +. The button switch, and then horn are connected to one prong on that. I have a - ground coming off the horn and have tried grounding that to many different places, including another grounding location that has a different lead going back to the batt -

Thanks for the help.

 

Horns are very sensitive to needing full voltage, and plenty of amps. They need good wiring and maybe even to have the engine running. Possibly yours needs a slight adjustment, since it works direct from the battery. There should be a screw adjuster on it, possibly sealed.

Another pro-tip... they won't work right if mounted rigidly. They need to be able to vibrate, on a rubber or flexible base.

 

very true
and OP didn't say if he was operating horn with 12V or ground with push button switch or horn button on wheel

 

Thanks guys. I’m also starting to think I might need a horn relay, as the button/switch may not be able to handle the power load. But even when I remove the button and try touching the wires there... nothing.

Twin2, I’m not sure what you mean. I have a new Oreily basic button with the rubber cap, mounted on the dash panel. No horn on the steering wheel. The button is set to connect the 12v circuit when depressed.

Here’s how I’m currently set up.

 

just a example of mine . two connections on horn
Red is 12V - always hot
Black is grounding wire to steering wheel
no relay required
as pete mentioned horn can not be mounted solid . must beable to vibrate

 

Update: I tried a different horn I just received in the same setup... and it’s works perfectly! I’m not going mad after all!

I’m guessing the old Hella was just being finicky about having perfect volts or something, as it worked when checked on the battery leads.

Thanks guys!

 

my guess is that the original horn will probably work fine with a relay. Regardless, horns pull a lot of amps so a relay is probably a good idea.

 

Some of these horns are polar sensitive. They are marked + -.

 

Whoever gave you the free horn needs a kick in the butt.

 

Possibly the original needs a slight adjustment. Look for an external screw/locknut, which sometimes may be 'sealed'.