67 Horn Problems

[Gerard F.]

Wondering if anyone has run into this problem before.

I had a problem with the 67 signal switch a few weeks ago. The horn would not blow. Traced it down to a worn contact on the signal switch. Replaced the switch and then everything worked fine.

Now I have a problem with the horn blowing intermittently when I make a hard right or left turn. Otherwise going straight, the horn works just perfect. I have my original 67 horn button on the steering wheel, the horn contact under and the original canceling cam and signal switch shield. The only thing replaced in the signal column is a repro signal switch (and for the fourth time).

Could it be the original horn contact below the horn button? It doesn't seem to spring as much as it used to, when the car and I were a lot younger.

Is it possible to put the steering wheel on too tight.

Please respond if you have had the same problem or know a solution.

[Richard M.]

Re: 67 Horn Problems

Jerry, Usually it's caused by too much play some area. It's a trial and error to find the culprit. You cannot get the wheel too tight, but not too much to strip the shaft threads or nut. One thing I've learned, when reproduction parts are used with original parts like this, what worked before may not work afterwards. Sometimes a few adjustments are needed to make everbody happy.

Things to check: (I recall yours is a standard column, right?)

The upper bearing. If too much play, it can cause erratic movement of the shaft & wheel assembly, and enough to make intermittent contact of the plunger to the side of the housing/hub. Check side to side play of the wheel without turning. There should not be a large shift. Not more than 1/32" or so IMO.
P3140003.jpg
The bearing/housing assembly(above right) is not available in reproduction. Replacement bearings are available but you have to do some creative work to remove the original from the bearing housing and epoxy or stake the new one in.



A misaligned horn button stand/contactor. Check that the "L" shaped tab that pushes on the backside of the cancel cam/horn contact isn't hitting the side of the wheel hub hole. Sometimes all that's needed is to loosen the 3 mount screws a bit and relocate the contactor slightly then re-tighten. Also check the plastic rivets for wear or breakage. If that circular ring touches the black ribbed horn button locks it'll trigger the horn by design. It must be isolated until the button's pushed of course.



A loose or defective cancel cam/horn contactor ring. This is the part that touches that copper/brass button in the turn switch assembly.



A short of the horn wire to the mast jacket, rubbing when wheel turned hard. (IMO I doubt that is happening though)
P3140004.jpgP3180034.jpg


As mentioned, trial and error and close observation of all insulated areas can help find the problem.

Good Luck,
Rich
p.s. BTW, I have the same problem on a '60 I'm restoring. I need to use the same trial and error techniqes, but just looking at different hardware. I've been procrastinating on it but it's part of the "punch list" after I get other priorities resolved.

[Gene M.]

Re: 67 Horn Problems

Jerry,
Just a small add to what Richard has already stated. The upper bearing does not have a good surface to contact/preload the inner race. I added a small ring to give a good surface that contacts the inner race only on the steering wheel side. My ring is .035" thick round fitting close to shaft.

[Gerard F.]

Re: 67 Horn Problems

Rich,

Thanks for the detailed review of my problem. I'm suspecting the original worn horn contact, and canceling cam with a loose contact button. The only thing in my column that is not original is the signal switch, so I think after 46 years some of the parts are worn.

So I just ordered a new horn contact and cancelling cam and just about every screw set and part in the upper column from LIC. I'll be having fun troubleshooting when the parts come.

I'll let you guys know of the outcome.

[Ray G.]

Re: 67 Horn Problems

Corvette rag joint repair kit.jpeganother possibility

[Richard M.]

Re: 67 Horn Problems

Ray,

I gave that some thought too when he first asked, but if the ground floats I don't think it would cause the intermittent like he's seeing. I think it's a mechanical intermittent short up in the hub area. If the ground opens going to a switch, it just won't energize the relay, but........

.....I've heard of some strange things happening when the steering coupler ground floats. You can actually get a slight shock when you push the horn button with your bare hand as the ground path is now your hand passing through your body somewhere trying to flow through to chassis ground. I've never experienced it but others that I know have. Very strange, being low voltage and all, but it's proof that it's not the voltage that gets you.....it's the current! Lots of amps in the horn circuits, and because the horn relay coil switches ground via the horn button, the constant positive side of the relay coil is at the same potential as the relay contact + source tap, i.e. heavy gauge wire tap from the battery/alternator wiring.

Rich

[Gerard F.]

Re: 67 Horn Problems

Jerry, Usually it's caused by too much play some area. It's a trial and error to find the culprit. You cannot get the wheel too tight, but not too much to strip the shaft threads or nut. One thing I've learned, when reproduction parts are used with original parts like this, what worked before may not work afterwards. Sometimes a few adjustments are needed to make everbody happy.

Things to check: (I recall yours is a standard column, right?)

The upper bearing. If too much play, it can cause erratic movement of the shaft & wheel assembly, and enough to make intermittent contact of the plunger to the side of the housing/hub. Check side to side play of the wheel without turning. There should not be a large shift. Not more than 1/32" or so IMO.
[ATTACH=CONFIG]49510[/ATTACH]
The bearing/housing assembly(above right) is not available in reproduction. Replacement bearings are available but you have to do some creative work to remove the original from the bearing housing and epoxy or stake the new one in.



A misaligned horn button stand/contactor. Check that the "L" shaped tab that pushes on the backside of the cancel cam/horn contact isn't hitting the side of the wheel hub hole. Sometimes all that's needed is to loosen the 3 mount screws a bit and relocate the contactor slightly then re-tighten. Also check the plastic rivets for wear or breakage. If that circular ring touches the black ribbed horn button locks it'll trigger the horn by design. It must be isolated until the button's pushed of course.



A loose or defective cancel cam/horn contactor ring. This is the part that touches that copper/brass button in the turn switch assembly.



A short of the horn wire to the mast jacket, rubbing when wheel turned hard. (IMO I doubt that is happening though)
[ATTACH=CONFIG]49512[/ATTACH][ATTACH=CONFIG]49511[/ATTACH]


As mentioned, trial and error and close observation of all insulated areas can help find the problem.

Good Luck,
Rich
p.s. BTW, I have the same problem on a '60 I'm restoring. I need to use the same trial and error techniqes, but just looking at different hardware. I've been procrastinating on it but it's part of the "punch list" after I get other priorities resolved.

Thanks very much Rich,

I followed your advice on troubleshooting and got the problem fixed. It turned out to be the combination of an improper signal lever screw and a badly worn cancelling cam. Here's my report and some pictures:

I started out checking out the horn contact button:




It seemed OK except that the lower mounting screw was stripped in the housing and loose. So I pulled the horn contact to see if the hard right or left horn blow would repeat:




The problem repeated without the horn contact in place, so I knew the problem was deeper.

So I went and pulled the steering wheel and hub and nothing was obvious:




But in pulling the cancelling cam the problem became obvious:




See that tear in the plastic signal shield to the left of the shaft. That's the position of the signal lever bolt and where the canceling cam was rubbing against the shield.


(See next post for continuation)

[Gerard F.]

Re: 67 Horn Problems

(Continuation of previous post)

In removing the plastic switch shield, the rub point reveals itself, the hardware store 8-32 signal lever bolt:




In replacing the signal switch numerous times, I had found that the original signal lever screw (which I still have with the original switch)was at least a 1/4" too long. so I replaced it with a 1/2" 8-32 round head screw and two lockwashers.
It just stuck up too far.

Then I took a good look at the original cancelling cam:




I found that the bearing surface of the cancelling came was worn at least a 1/16" compared to a replacement cancelling cam:


The combination of the round head bolt and the worn bearing surface also put a little bow in the cam.

So I replaced the lever screw with a pan head 8-32 x 1/2" SS screw and used one lock washer:





Then I put in a repro cancelling cam, and checked the clearance at the bolt head, its at least 1/16" and there is no rubbing on turns:




Putting it all back together, my problem with the intermittent horn blowing on hard turns was solved. It also turns a lot smoother without any rubbing sound.
Problem solved.

[Gerard F.]

Re: 67 Horn Problems

Gene,

You are right on. I found that my original 67 cancelling cam had worn its plastic bearing surface about 1/16". A ring would have helped my problem with the original cancelling cam, but I had a replacement cancelling cam handy.
See my posts below on the resolution of my horn problem.

[Richard M.]

Re: 67 Horn Problems

Good job fixing that Jerry. Your detailed thread will help others in the future as well.

Nicely done!

Rich