Horn frustration

[bohemianjeeper]

Hey, I'm new to CJ7s and have read through some of the threads already on horn issues, yet for the life of me can't seem figure out what is going on with my horn. The old horn tested bad when plugged directly to the battery. Okay, so I bought a new horn, plugged it in. Still nothing. When I depress the horn button on the steering wheel, I can hear the relay under the dash clicking. I checked 2 fuses for what I think might be for the horn in the middle of the fuse box, one marked for dome/ctsy, the other right underneath it for tail, and they both are good. Any ideas what I'm doing wrong here?

 

[Hedgehog]

First some understanding about how a horn is wired. You horn is on a continuously hot circuit, it's not switched. Next, your horn is ALWAYS hot, check to see if you have a full 12v at your horn. The horn button actually grounds the circuit allowing the horn to work. It's generally a very direct circuit. You need to find that clicking relay and check to see if its got 12v going in on one side of the main circuit and a ground on the other. The relay part is a simple electric switch, but I can't help you there. Hope this helps at least a little.

 

[Lumpy Grits]

My SWAG is a bad relay. BTDT-
LG

 

[Jimbos76cj]

Im going to disagree with hedgehog a little bit. If your horn only has one wire going to it then its not hot all the time. When the horn button is depresed it trips the relay that provides power to the horn. The power does it elfin magic making the horn work provided it has a good ground. The relay on the other hand I beleive uses the ground to switch it. Once the relay closes it provides power to the horn.

Now the biggest over looked issue for items not working that are mounted to the fenders or grill is that over the years corrosion builds up in between the body panels and reduces or eliminates the grounds. So if you have some extra wire run a wire from the negative side of the battery to the mounting screw on the horn then try pushing the horn button again.

Same issue happens with starter solenoids.

 

[Jimbos76cj]

IF that doesnt work trace the wire from the horn back to the fuse block mount on in the engine compartment. IF there are no breaks in the wire seperate the block halves and check for funk in the block. If your handy with a multi meter or test light you can also probe the back of the interal fuse block to see if there is power going to its contector.

 

[Jimbos76cj]

My SWAG is a bad relay. BTDT-
LG

Im going bad ground. Ive trouble shot several horn circuits on CJ's and YJ's and if the relay is clicking it is almost always a bad ground.

 

[jdcaples]

I agree it is probably a bad ground..... Regardless, sometimes new parts are also bad.

You said the old horn tested bad directly connect to the battery. Did the new horn test good connected the same way?


-Jon

 

[Hedgehog]

Jimbos76cj - I've never seen a cold CJ horn, all and I mean ALL the CJ horns I've seen were hot waiting for a ground, why .... I don't pretend to know. To test the horn, put a 12v hot line to one post on the horn, run a grounded wire to the other post. If that doesn't work, switch the posts and try again. In my world either side usually works. But, hey what do I know about the couple dozen horns I've changed over the years.

 

[ThisGuyUKnow]

There is a horn relay that most likely is bad. The horn button on the column activates the relay which then passes 12v to the horn which is grounded to the fender.

First test the relay or change it. If that doesn't work I'd check the ground to the horn then troubleshoot from there.

 

[Jimbos76cj]

A most of the horn issues I've seen have been

1) bad contact in the horn.. or the spring loaded plunger is broken/missing. The plates get rusty and wont make enough contact to kick the relay. This is a freebie. Pop the horn cover off, remove the 3 screws that hold the the button assembly down and sand them clean and give it a try.

2) Bad relay. Swap em.

3) Bad horn/bad ground at the fender.

4)broken wire in the column.

I think I covered almost all the issues that can be found with the horn. When I trouble shoot a horn
1) Push the button. If the relay clicks but no horn its either wire going to horn, ground or horn it self.

2) relay doesn't click I pull apart the button and check wiring to the relay along with the relay it self.

When testing the horn its important to provide it a hot and ground source since even if you provide it a 12volt source the fender ground could be corroded so it wont complete the circuit.

 

[Chasinmendo]

Where can one get springs for the horn contact. I recently got this JEEP and found that the spring was missing.

 

[Torxhead]

Short of purchasing a new horn kit, you could find one at someplace like a hardware store or industrial supply.

 

[Neuner]

Where can one get springs for the horn contact. I recently got this JEEP and found that the spring was missing.

I think mine was missing and I used a spring from a ball point pen.


So where is the OP to this thread? Looks like another one-hit-wonder...

 

[jdcaples]

I think mine was missing and I used a spring from a ball point pen.


So where is the OP to this thread? Looks like another one-hit-wonder...

New members have been reporting problems logging in after initially registering. They're fine until the first session expires. Then they're locked out, have to register again to post.

I'd put up with that once or twice, then I'd give up.

-Jon