ANOTHER Horn Problem - Need Help Please
 

I'm redoing my interior and part of it is a new steering wheel. While I had the wheel off, I took off the turn signal mechanism and installed a new upper bearing. When I try to put it back together now, I got as far as torquing the steering wheel down when the horn started honking. From messing around with it, I know it has something to do with the spring loaded copper button on the turn signal mechanism (see first picture). If I press the copper button with my finger, nothing happens, but when I put the (brand new) turn signal cancelling cam on (see second picture), and push into place, the copper button does down and the horn starts honking. Am I doing something wrong, or do I need to by a new turn signal mechanism (which is only a year old) or what?

http://67-72chevytrucks.com/vboard/p...ictureid=13627
http://67-72chevytrucks.com/vboard/p...ictureid=13628

BTW, a good little tip someone passed on to me - Instead of pissing all my neighbors off with the horn, I connected the wire to a light bulb to see when the horn was on or off. Worked great...
http://67-72chevytrucks.com/vboard/p...ictureid=13629

:gmc2:

Re: ANOTHER Horn Problem - Need Help Please
 

bump for some help.

Re: ANOTHER Horn Problem - Need Help Please
 

TTT -C'mon, I know someone out there must know about this...

:gmc2:

Re: ANOTHER Horn Problem - Need Help Please
 

it looks right from there, might need more pics of what the horn set-up is above the cancel cam. If the pin on the cancel cam is hitting metal I think you'll have a problem. The instructions with those things usually tell you to cut some off to shorten it.
If I understand the horn wiring correctly, the horn grounds to the metal in the column, mine grounds to a steering wheel bolt. So if a wire isn't insulated/pinched, or that cancel cam pin hits metal, you'll sound the horn. Might be just a bit too long so it contacts something only when you tighten down the wheel nut.
Just my guess with very little experience.

Re: ANOTHER Horn Problem - Need Help Please
 

The horn starts going off with just the cancel cam and nothing above it. All I have to do is push it into position and that's when the horn starts honking. I can push the copper button on the signal switch all the way in with with my finger and nothing happens. But when I put the cam on and seat it (far enough to depress the copper button) that's when the horn goes off.

Re: ANOTHER Horn Problem - Need Help Please
 

It's been too many years since I had mine apart.... but grounding that copper button will operate the horn relay, which of course blows the horn. The horn doesn't blow when you push the copper button because your finger isn't grounded. If you touch the button with a test wire connected to ground, the horn will blow.

That doesn't exactly answer your question..... just trying to help you with a bit of info. The brass ring on the cancelling cam is getting grounded, which then grounds the copper button.

What dcasalena said about shortening the cancelling cam pin might be right..... it kinda rings a very faint bell with me, but like I said it's been way too many years.

Re: ANOTHER Horn Problem - Need Help Please
 

ttt

Re: ANOTHER Horn Problem - Need Help Please
 

Not sure if I can help but here is a exploded diagram of a column...maybe the switch contac support may be the culprit...item35........and just a tip that I use is to place a penny on the shaft end to pull the steering wheel with the puller.....saves on marking up the shaft

Re: ANOTHER Horn Problem - Need Help Please
 

I don't know what year truck you are working on...but if it is 1971 or earlier...then it looks like the wrong T/S Cancelling Cam to me...you should be able to insert a black pronged spring loaded connector into a cavity where the silver button is in your photo...the pronged connector has a wire which connects to the horn button at the steering wheel...so when you press the horn button...it completes the ground and the horn sounds.

Also...make sure the BLACK wire from the turn signal switch to the horn relay is not grounding in the column...this happens sometimes when replacing a turn signal switch if one is not careful threading the T/S harness through the column.

Re: ANOTHER Horn Problem - Need Help Please
 

It's a 71. The cancelling cam is brand new and it looks just the same as the old one, except not worn out. My thinking is that this leaves the turn signal switch (with the copper button) or a short. Before I spend money on the new T/S switch, I should check for a short. Electrical is not exactly my forte, so if anyone can tell me how to check for a short, I'd really appreciate it...

Re: ANOTHER Horn Problem - Need Help Please
 

First let's check your horn relay:

Connect your test light lead to a good GROUND and with all three connectors plugged in at the horn relay...touch your test light tip to the green wire connector on the horn relay...the test light bulb should remain off. If the test light bulb lights on the green wire...the horn relay is bad...replace it...end of problem.

If the test light bulb does not light when testing the green wire:

To check for a short to GROUND:

Connect your test light lead to a B+ source...then when you touch a GROUND source ( like a bolt or sheet metal ) with the tip of your test light the bulb inside your test light will light verifing you have located a GROUND source.

So to check to see if your horn wire is shorted to GROUND:

Disconnect the BLACK wire at your horn relay and touch the connector with the tip of your test light. If the test light's bulb remains off...then you know there is no short to GROUND in the T/S switch harness. Repeat this test with the cancelling cam installed and see what the light does.

Re: ANOTHER Horn Problem - Need Help Please
 

First of all, thanks for all this info. I just replaced my turn signal switch to only put everything back together. Hooked battery up and horn blared!!!! Through trial and error, what I found out was the POS reproduction parts LMC sell have a different backing plate where the black wire attached. That STUPID plate was grounding out on the column causing the horn to engage. So incredibly frustrating!! However, filed the tab down and no more horn blaring.

Re: ANOTHER Horn Problem - Need Help Please
 

Old thread revival, nothing wrong with that (it proves you searched!), and I'm glad you got it to work correctly!

Re: ANOTHER Horn Problem - Need Help Please
 

It's amazing the trouble we have to go through to modify aftermarket parts so that they will work on our trucks...It's like nobody at the factory or parts supplier has actually used the parts! If it's not NOS, you'll be wallowing, filing, rewiring, cutting and welding, sanding and repainting, etc, etc.

Glad you worked it out!

Re: ANOTHER Horn Problem - Need Help Please
 

I am not getting sponsored or have been offered discounts for what I am about to write: But, that’s why I buy my parts from Early Classic. Granted, I haven’t done a restoration by any means, but these guys at ECE have trucks like ours and have tested many or all of the parts on their trucks (definitely the ones they manufacture). With that said, that’s why their customer service is stellar when you ask about installing a part you just ordered. I was actually referred to them by a friend, for those reasons, and now have experienced it on numerous occasions. They’re the only company I’ve ordered Repopped parts from and haven’t had one issue.

I’m glad you got your horn worked out!!! I know the feeling. Glad it was a simple fix!!