Topic: Help w/ horns

[68 S Code]

Haven't been able to get the horns to work. Tried a test light at both connection points and I do get a light. So I believe the steering wheel is ok as is the fuse and wiring. Is it that I'm not getting a ground through the paint at the core and on the horn bracket? What is the small Phillips head screw for? If I added a ground wire to it and used that as a temporary ground can I test the horns to make sure they work? If they work then I should strip some paint at the core and horn bracket?

[bryancobb]

Remove each one and test it in your hand directly to 12VDC.  If it doesn't blow there, the car is not the problem.

[cobrajetchris]

What is the small Phillips head screw for? If I added a ground wire to it and used that as a temporary ground can I test the horns to make sure they work? If they work then I should strip some paint at the core and horn bracket?

The small Phillips head is for adjusting the tone/pitch of the horn. Another thing to check is to make sure the attaching bolts have serrated washers vs. flat washers as the serrated ones will bite into the metal for a good ground.  CHRIS

[Bob Gaines]

Haven't been able to get the horns to work. Tried a test light at both connection points and I do get a light. So I believe the steering wheel is ok as is the fuse and wiring. Is it that I'm not getting a ground through the paint at the core and on the horn bracket? What is the small Phillips head screw for? If I added a ground wire to it and used that as a temporary ground can I test the horns to make sure they work? If they work then I should strip some paint at the core and horn bracket?

It was somewhat common for the engine bay paint to be thin at the core support for grounding reasons. i have seen some example that was almost bare steel.I always strip a little paint under where the horn mounts as well as the horn bracket and use some dielectric grease to keep it from corroding to get a good ground and not have it be visible . 67 Shelby's are notorious for the horns not working and this is a must do on any of them IMHO. Do what byrancobb writes. The Philips head screw adjusts the pitch and you can sometimes get a non working horn to sound by working it back and forth. It adjusts the contact inside the horn. Bob

[68 S Code]

Well I tried the suggestion about removing some of the paint at the horn bracket and core. Took them off and used the battery for direct power. Nothing. Someone locally suggested whacking it a couple times with a rubber mallet to loosen things up inside. Well I got a sound but it's like a viabtating diaphragm. Don't know if I shouldn't just look for a working pair. I've tried looking for a date code but see nothing. May be filled in with primer and paint but don't really know where to look.

Bob regarding the electrical items and zinc dichromate observation I see that those pitch adjusting screws on mine are ZD. Also cleaned up a nicer rear license plate light and all parts are ZD. Also found that the retaining plates for hood light sockets are ZD. Took some pics to post on site so look for them in a few days.

[Bob Gaines]

Well I tried the suggestion about removing some of the paint at the horn bracket and core. Took them off and used the battery for direct power. Nothing. Someone locally suggested whacking it a couple times with a rubber mallet to loosen things up inside. Well I got a sound but it's like a viabtating diaphragm. Don't know if I shouldn't just look for a working pair. I've tried looking for a date code but see nothing. May be filled in with primer and paint but don't really know where to look.

Bob regarding the electrical items and zinc dichromate observation I see that those pitch adjusting screws on mine are ZD. Also cleaned up a nicer rear license plate light and all parts are ZD. Also found that the retaining plates for hood light sockets are ZD. Took some pics to post on site so look for them in a few days.

you might be able to get the vibrating to change into a more horn like sound by adjusting the screw while applying power working it back and forth. If not I would try another set instead of rebuilding only because they a relatively prevalent and rebuilding is time consuming and usually more expensive. I figure you already know this but just in case there is some misunderstanding the pitch adjusting screws are painted black along with the entire horn. Bob

[CharlesTurner]

You might try soaking the horns in evaporust.  I did this with a set recently and they work perfect.

[ruppstang]

Good idea Charles, I have to try that. Marty

[Bob Gaines]

Good idea Charles, I have to try that. Marty

Let us know how that works out. iquiring minds want to know. 

[68 S Code]

Well bucket of evaporust is downstairs so I guess i can try it. What do I have to lose. Taking out the pitch screw at least starts to corroborate the theory that Bob has on electrical components having ZD finish. Saw a set of original unrestored 68 fog lights today. I could see the ZD finish on the portion of the fog light bucket which has the mounting stud. This circular portion is attached to the main bucket via rivets and then the bucket was painted argent. Looked like the stud was masked to prevent paint. The special washer was also ZD plated (on the reverse side finish was protected) and the nut I am assuming was phosphated as it was rusty. Just noticing more and more electrical components with the ZD plated finish. Passing along what I'm finding. These are all 68 pieces I'm referring to.

[Oz390]

As long as evaporust doesn't mess with plastic or copper you should be OK.  I found once you get some noise a good squirt of penetrating oil or WD40 into the adjuster screw hole and stuffing a rag in the end and running it for a while off a battery usually frees them up.

The date codes are stamped into the long edge of the outlet on the face of the scroll.  Looking at the scroll side, along the long side of the opening they are usually stamped just below the lip.  Many are very faint, I'd say half I've seen are readable to some extent, few with full crisp stamps...

I don't have a photo but if you want one I may have a set in the shed that are blasted and can take a snap or two.

[68 S Code]

Thr evaporust worked great. Loosened up things inside and felt lime a diaphragm moving around. Cured the grounding issue but not making a horn sound from the column ring. Hear it trying to do something. If I use 12v from battery directly they work individually. Is there too much voltage drop with car not running?

[carlite65]

i have often found that cleaning all connections will help with the voltage drop. expecially the one at the bottom of the column.

[68 S Code]

What do you use to clean the female end if the pin connectors. Difficult to clean the slider connection at horn wire as well.

[midlife]

What do you use to clean the female end if the pin connectors.

I'm going to try evaporust later this week to see the effects upon copper wire and the insulation.  I'll report back.

What I've done in the past is use a grinding stone chucked in a hand drill to remove some of the corrosion.  It's not terribly effective, but will remove large scale and dirt.  I've also wrapped a bit of sand paper around a drill bit; that works better than the grinding stone, as I've yet to find a stone with the right diameter.