Horn doesn't work!
 

Horn has never worked and I'm finally getting around to fix it. Here are the facts:

1) replaced horn relay - still doesn't work

2) read this previous thread and it appears the assembly is correct as installed-http://67-72chevytrucks.com/vboard/showthread.php?t=706524

3) Photos below show my steering wheel cavity with horn parts removed (pin installed) and my parts.

4) Observation - My assumption is that when you press the horn button, it pushes down the pin inside the spring which then makes contact with the metal plate at the bottom of the small cylinder tube. This seems to me this is the way that it works. Assuming correct, I measured the length of the pin and it is 3/4", however, the depth of the cylinder measured from the bottom plate up to the edge of the base plate is at least 1 1/8". So there is no way the 3/4" pin could ever be depressed deep enough to reach bottom plate . Maybe I'm not analyzing correctly?

5) can anyone suggest a way I can test to see if horn works? I read in the above mentioned thread that some guy connected a test wire from the fully depressed pin to the steering column center bolt and the horn sounded. I tried hooking up a lead pushed down into the cylinder to make contact with the bottom metal plate (did not use pin) while touching other end to the center bolt and it did not work. ARGH!

Any thoughts, suggestions are welcomed!

Re: Horn doesn't work!
 

http://i14.photobucket.com/albums/a3...old%20horn.jpg

I have 3 older cars and the horns don't work on any of them.

Re: Horn doesn't work!
 

I have 2 old vehicles and the horn didn't work when I got them but they do now. :)
Stop when it works...
Ground the pin. No need to push it down. Listen for the click of the horn relay.
Ground the pin to the dash.
Ground the (not hot) terminal on the relay that comes from the column.
Apply 12V to the horn. Check the ground to the horn and try again.
Replace the horn and start over.

Re: Horn doesn't work!
 

Under the button should be a plastic sleeve, then a spring and then a brass or copper cup that extends down to make the contact.
http://67-72chevytrucks.com/vboard/s...button+install
.
.
.
.
.

Re: Horn doesn't work!
 

Hey Swamp- my plunger parts don't look anything like the ones in the GMC horn thread. As you can see in my photo, there is a spring, a 3/4" pin and a red 1/4" plastic bushing. Do I have correct parts?

Re: Horn doesn't work!
 

It looks like you have all of the correct parts but your assumption of how the horn works is incorrect. The Spring loaded pin is depressed all of the time and it makes contact with the metal disk at all times. When you push on the horn button it pushes the metal cup down, which pushes the center of the metal disk down and grounds it against the metal in the center of the steering wheel hub. This completes the ground connection and activates the horn relay which honks the horn....

The disk is the first piece to go inside the steering wheel(dome side up) then the metal cup, then the plastic retainer with the three screws. If you hold the metal cup in your hand and put the retainer down inside it you will see that the bosses on the plastic retainer fit snug inside the holes in the cup. Turn that assembly upside down and put the metal disk on it and you will see that the holes in the disk just fit over the bosses on the retainer also. That is the way it has to go together. It can be tough getting it all lined up down inside the steering wheel and keeping the metal disk in place. If the disk gets out of place and gets pinched between the steering wheel hub and the retainer, either the horn won't honk or it will honk all the time.

You may have to take a small screwdriver and push the metal disk up from the bottom after you have the screws snugged up to get it in place. When you have all of the parts installed and you push on the edge of the metal cup it should push down a little bit, it should not be solid. If it is solid or the horn honks when you hook the battery back up the studs are on the disk and not through it.

This is one of those procedures that is hard to put into words but fairly easy to do so I hope you can follow my rambling....

LockDoc

Re: Horn doesn't work!
 

http://i1262.photobucket.com/albums/...psnzwzn0vs.png[/QUOTE]

Re: Horn doesn't work!
 

This is another problem I have waiting for me.....my dad replaced the horn with a simple push button mounted under the dash. It works fine but is so hard to reach by the time you do the reason for blowing is long past. :lol:

Re: Horn doesn't work!
 

LocDoc, I actually read your previous thread from some time ago when I first initiated the "fix". So thanks again for response. Now that I know I have the correct parts, as well as the correct assembly and not to mention the correct theory I'll reassemble. Since I already installed a new horn relay I'm going to test via "franken" suggestion next.

Ground the pin. No need to push it down. Listen for the click of the horn relay.
Ground the pin to the dash.
Ground the (not hot) terminal on the relay that comes from the column.
Apply 12V to the horn. Check the ground to the horn and try again.
Replace the horn and start over.

Re: Horn doesn't work!
 

Sounds like that should work. You don't need to go to the dash to ground the pin, just use a screwdriver to ground it to the steering shaft.

The terminal on the relay that you need to ground would be the one with the Black wire connected to it. When you ground that terminal the relay should click and the horn should sound.....

LockDoc

Re: Horn doesn't work!
 

take the horn off and apply 12v to the horn and make sure you ground the body if nothing happens try spraying a big bunch of wd40inside the horn body let soak for awhile then try again and see if it makes noise keep spraying wd40 into it to clean up the diafram inside the horn that beeps

Re: Horn doesn't work!
 

Update: I removed one of the horns and confirmed its working when wired up directly to 12v and grounded. So, next I ran a new ground wire to the black wire terminal on the relay, per Leon's suggestion. The good news is when I touch wire to a known good ground contact on the dash I hear a click...woohoo! However, if I leave the new black wire grounded, the horn sounds constantly. If I disconnect the new ground I installed and press the horn button, NOTHING! Thinking maybe I installed the horn assembly incorrectly, I removed it and tried to use screwdriver to ground from the pin to the steering shaft....still NOTHING!

Ok guys, what am I doing wrong?

Re: Horn doesn't work!
 

I guess the next step would be to try what franken suggested and connect your temporary ground wire to the dash somewhere (preferably to the same place as you did before) and touch the other end of the wire to the spring loaded pin and see what happens.

LockDoc

Re: Horn doesn't work!
 

Check the connection on the horn itself. Mine has fallen off several times in the past, then I fixed it. Make sure the horn is grounded good to the support. Remove the paint under the mount.
Take a jumper wire from battery and put it to the horn to verify it works.:chevy:

Re: Horn doesn't work!
 

Today's update...

@Leon - I hooked up a wire from the dash ground and touched the pin and the horn sounded. I did have to depress the pin down into its cylinder. It seems as if the horn contact is working correctly by pushing down on the cup. I also tried to touch the screw heads with the grounded wire and the horn sounds! I have assembled and installed the horn contact (w/ domed higher side facing up) exactly as the diagram above from 66clow.

Re: Horn doesn't work!
 

I'm betting that the metal disk is pinched between the plastic retainer and the steering wheel hub. If you look at the installed components from above is the metal disk centered as compared to the metal cup? (even around the outside). Also make sure that the metal hub inside the steering wheel is bright metal with no overspray or rust on it.

LockDoc

Re: Horn doesn't work!
 

Subscribed - I'm having the same issue. I'm to the point where I'm just going to buy the bumper sticker that says "Horn Broke - Watch For Finger!" :lol:

Re: Horn doesn't work!
 

Good stuff Leon but I actually thought of that so I took some fine emery paper and removed the slight amount of corrosion that was on the metal disc. I also cleaned up the base plate with the emery paper. And finally, I can see the disc is centered around the steering shaft. I tried moving it around with a small screwdriver just to see if if I could "seat" it! UGH! I really don't like driving without a horn! Do you think there is a possibility that horn contact components could be bad? I can't hardly see how/where they could be bad. Worth the $20 investment from LMC for new parts??????

This weekend I tackle the non-working backup lights! It never ends.......

Re: Horn doesn't work!
 

I wouldn't think they could be bad since it works with the jumper wire but I guess anything is possible. Try backing out the three screws a little bit and see if that makes a difference. Did you clean the brass contact ring around the bottom of the cancelling cam under the steering wheel?

EDIT: Try the jumper wire from the dash to the pin again but push the pin all the way down this time. Does it still honk?

LockDoc

Re: Horn doesn't work!
 

I tried loose and tight....no diff. Regarding the brass contact ring, I'm not sure of it. Do I need to remove the nut on the steering shaft to access it? Do I need a puller to access the cancelling cam? I have not unassembled anything further than you see in my initial photos.

BTW - thanks for all of your help, I really appreciate it!

Re: Horn doesn't work!
 

Yes, you would need to pull the steering wheel off to clean it.

I edited my previous post. read the edited part and try it.

LockDoc

Re: Horn doesn't work!
 

ok, when I touch ground to pin fully extended outward towards me, no horn. When I touch pin to fully depressed pin, still no horn! I had to be careful when trying to test with fully depressed pin because if I touched any parts of the metal base plate near pin, the horn would sound. So I put some tape around area to be sure I wouldn't inadvertently hit the base plate and when I touched the ground wire to the depressed pin, no sound! Now what?

Re: Horn doesn't work!
 

Here is another post to read, http://67-72chevytrucks.com/vboard/s...d.php?t=515103 ... I thought I had mine figured out, it lasted about 4 days before it woke my son up at 2 am.

Re: Horn doesn't work!
 

Call me a nut but its an absolute requirement for me that all the LITTLE things like ashtray lights and horns and lighters work. Drives me crazy that my washer pump doesn't work at the moment!

I guess so many years of driving an old car with butchered wiring and cigarette foil fuses will do that to you!

On my "winter beater" C10 in the 80s my ignition key stopped working so I hooked it up to the horn (disconnected the actual horn). So you'd turn the key to on and hit the horn. Great anti-theft if it was worth stealing (I guess anything is worth joyriding). Only got cut off and hit the horn to a horrible grinding sound once.

I was impressed the horn relay can handle solenoid levels of current, but it worked for years.

Re: Horn doesn't work!
 

Looks like you will have to pull the steering wheel off and check the parts in the cancelling cam and turn signal switch. The problem has to be in that part somewhere....

LockDoc