# Horn broken



## papereater (Sep 16, 2016)

People,

My old 87 Sunbird GT, horn does not honk. I applied 12V directly and the horn honks, but not from the push button switch on the steering wheel. So, I measured voltage on that switch and got 10.2V, but when I tested it with the test light the light did not blink on. I thought it may be a bad ground, but should I be chasing this voltage idea, since I am getting only 10.2V?

Thanks, people.


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## papereater (Sep 16, 2016)

I also tested for continuity with the Ohmmeter, and put it on "ring" mode, and got no ring anywhere I tested for continuity for the ground (one terminal on center bolt of steering wheel, other on the brass tab on horn switch, while depressing the horn). No ring- isnt that bad sign for a ground connection? 

Thing is, the no ring was on BOTH horn switches (I have 2 horns, one on each side of the steering wheel. )


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## Nealtw (Jun 22, 2017)

Do You have a relay just under the dash near the steering column


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## papereater (Sep 16, 2016)

Thanks, Neal! Now, I can check but is that diagram from an actual sunbird shop manual? Or just a representative drawing typical for many cars?


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## Nealtw (Jun 22, 2017)

papereater said:


> Thanks, Neal! Now, I can check but is that diagram from an actual sunbird shop manual? Or just a representative drawing typical for many cars?


Not sure, 25 years ago i changed one a Buick Skyhawk,same body style but not sure where it was.


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## papereater (Sep 16, 2016)

Nealtw said:


> Not sure, 25 years ago i changed one a Buick Skyhawk,same body style but not sure where it was.


Close enough, Neal. I found the relay! It has a burnt contact. Hopefully, that is the culprit. Gonna see if Rock auto has it. Thanks for the fast replies/help!! I will advise on progress once I install it.


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## huesmann (Aug 18, 2011)

Could be a busted clockspring.


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## papereater (Sep 16, 2016)

huesmann said:


> Could be a busted clockspring.


Hmmmm, Didnt know my 87 sunbird had one. Do these old cars have clockspriings? What does a clockspring do?


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## iamrfixit (Jan 30, 2011)

Clock spring is a ribbon cable assembly that can wind looser or tighter as you turn the wheel. It's set to a mid point during install so the 3-4 turns the wheel will make can't wind it fully tight and break it. The clock spring allows for a fully wired and uninterrupted connection for the numerous wires required for the air bag, horn and other wheel controls. 

If the vehicle doesn't have an air bag or steering wheel controls, it probably won't have a clock spring. Most older vehicles used a more low-tech approach with a sliding ring arrangement for the horn. Couple contacts on one side and brass rings on the other. This makes a fairly reliable connection but not the 100% wiring integrity required for an air bag. Dust and dirt or cleaning products can work their way in between the wheel and column and interfere with the rings making contact. They can also wear over the years.

Very likely you also have a horn relay hiding somewhere. Older vehicles rarely had a centralized location for relays like modern cars do. Most just clipped on the firewall or up under the dash along the wiring harness somewhere. Finding them can be tough if you don't have a manual to guide you. Terminal corrosion is a common problem with fuses or relays, as well as the relay itself failing.


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## chandler48 (Jun 5, 2017)

Visiting NYC, San Francisco and Chicago, I was amazed at the use of horns during traffic situations. Horns blaring like they would solve the traffic jam in some way. Compared to Atlanta, where no one uses their horn, unless they are transplants from aforementioned cities.

I agree with the relay thingy.


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## GrayHair (Apr 9, 2015)

I don't think GM used a "clockspring". Horn electrical connection from the steering column to the steering wheel is through a slip-ring on the bottom of the *cancel cam* (an "age appropriate" version shown). The cancel cam rotates with the steering wheel and is located just under the notched steering wheel *lock plate*. The wire from the steering wheel mounted horn "switch" is placed in the tube on the "far" side of the cancel cam shown and is held in place by a plastic sleeve with a projection that "locks" in the notch in the tube. A spring-loaded cylindrical contact in the *turn signal switch assembly* contacts the cancel cam's slip-ring to complete the electrical connection. The tube on the cancel cam passes thru the cut out area about 12 o'clock on the lock plate.

The cancel cam got its name because the two lobes near the top of the shoulder release an activated turn signal, canceling the turn signal operation.

*EDIT: * I found the operation of the turn signal switch assembly mechanically interesting and innovative.
1. You move the turn signal lever in one direction or the other and it latches.​2. While you turn the steering wheel in the direction of the turn, the assembly remains latched.​3. When you turn the steering wheel in the opposite direction to straighten the wheels, the assembly unlatches.​A lot going on in a small space. If you get the chance to see one in action, you just might agree. 😊


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## papereater (Sep 16, 2016)

So good to know all this, people. Thanks. I learned a few things about my old car. So, no, I do not have air bags (maybe they were still in the future in 1987, right?) So, even though I ordered my new relay yesterday I did more checks, Actually got down there with a light. and put a jumper wire across the orange and green wires in the relay (with old relay removed) and the horn sounded! That means gotta be a bad relay, I figure. Also, test light between the Orange (hot) and ground produced a light on the test light. 

Glad I dont have to remove the steering wheel, etc. Anyway, thanks to all here who offered advice/help. Will report back when I get the relay.


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## GrayHair (Apr 9, 2015)

IIRC, GM first offered airbags in the '70s, and only on some models at first. Back then, who would have believed that they would become ubiquitous!


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## papereater (Sep 16, 2016)

I got the new relay, and popped it in, and horn still does not work. How depressing, especially after I followed the shop manual's step by step instructions on troubleshooting. Got no choice but to go back and do it all over again. From step 1.


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## GrayHair (Apr 9, 2015)

Here is something you may want to try.
1. Remove the horn trim from the steering wheel (phillips screwdriver or 7mm socket and disconnect the trim from the tube on the cancel cam.​2. If you look at the cancel cam link in post #11, you will see that the bottom of the cancel cam's tube is blocked by the brass slip-ring.​3. Take some wire, hold one end on the brass slip-ring through the tube and scrub the other end on bare metal in the steering wheel.​If the horn blows, the problem is the switch in the horn trim you removed.
If it doesn't blow, the problem is between the slip-ring and the horn (probably between the slip-ring ands the horn relay).


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## papereater (Sep 16, 2016)

Thanks, Gray, Will try that as soon as I get back out there, have nothing to lose. Meanwhile, what do you think about this: manual says if test light does not light when connecting terminals HOT and black wire, look for open in black wire. Doesnt this mean that if I touch both ends of the black wires (relay end and horn assembly end) and I get a BEEEP sound with my ohmmeter, isnt that confirming that I do not have an open? Yet, when I touch the relay black with the orange HOT I get test lighting up.


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## papereater (Sep 16, 2016)

Also, to get to the cancel cam, do I have to pull the steering wheel?


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## GrayHair (Apr 9, 2015)

No need to pull the steering wheel to get to the upper part of the tube on the cancel cam. Just follow the wire from the horn pad. Some retainers in the cancel cam tube have to be rotates CCW slightly to release them while other retainers have a ridge around the perimeter and just pull out.

Depending on the VOM, beeping may come from a continuity test (continuity between two points). If you are using a VOM in place of a test light, you should be looking for DC voltage (set VOM for more that 12 volts, unless it is auto-ranging).

Below is rough block diagram of a common automotive horn set up showing the battery, horn relay, horn switch and horn. Wire colors should be different from what you have to hopefully reduce confusion.







The chassis of the car is connected to the negative side of the battery and acts as a wire to complete a circuit. Unless the horn is mounted on plastic, this should be representative. Since I used a symbol for chassis ground, I'll call it ground (negative of battery). 
1. Depressing the horn trim on the steering wheel closes the horn switch which connects to ground, completing the circuit for the coil relay.​2. The relay contacts close applying completing the circuit to the horn.​​A test light connected *to ground* would light on the red wire and *may* light on the yellow wire (depending on the resistance of the relay coil) and *may* make the relay activate (depending on the resistance of the test light's filament). It would not light on the blue wire unless the horn is sounding.

A test light connected *to positive* of the battery would light on the case of the actual horn (may have to scratch away paint or surface corrosion) and on the bare metal of the steering column (under the horn trim).

I write as basic as possible since I never know who might be trying to use my ramblings.


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## papereater (Sep 16, 2016)

Geez, you sure know a lot of auto stuff, Gray. so glad you (and others) are on this auto forum. So, your post got me thinking, and i re tested the blk/org wires WITH the horn depressed, and test light glows!! Yipeeeee. I was testing without depressing the horn! Popped in the new relay and horn works great. We did it, Gray. I was worried that something way more serious was up, like an open wire.

Anyway, thanks very much! Im sure something else will break on my 34 year old car in the next year or so....LOL.


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## GrayHair (Apr 9, 2015)

Thanks for posting your resolution. I spent a lot of years in the top part of steering columns and have always been interested in electronics. Just things I enjoyed. Hope I was of some help.


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## huesmann (Aug 18, 2011)

GrayHair said:


> Thanks for posting your resolution. I spent a lot of years in the top part of steering columns and have always been interested in electronics. Just things I enjoyed.


Gone in 60 seconds?


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## GrayHair (Apr 9, 2015)

huesmann said:


> Gone in 60 seconds?


Making ignition keys. Whenever a big used car lot got burglarized and their keybox was stolen, I would get A LOT of practice. On non-tilt wheel GM products using *spring retained* ignition locks (as opposed to *screw retained*), I could tear the column down, remove the lock and reassemble the column in around 7 1/2 minutes (not including making the key). This was 25-30 years ago.


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