1990 horn buttons?
Thread Starter
Racer
Joined: Nov 2004
Posts: 265
Likes: 0
From: Angleton Tx
1990 horn buttons?
My horn buttons don't seem to work all the time.
I'm not even sure what the assembly should look like once the gray
plastic caps are taken off. There are two copper plates that seem
to be on top of eachother and that is all.
The horns work great - just not the triggering part.
thanks!
I'm not even sure what the assembly should look like once the gray
plastic caps are taken off. There are two copper plates that seem
to be on top of eachother and that is all.
The horns work great - just not the triggering part.
thanks!
Melting Slicks
Joined: Jan 2004
Posts: 2,992
Likes: 0
From: Henryville IN
You can sometimes clean the copper plates with a pencil eraser and then spary a little contact cleaner on them so they wont tarnish so fast. But on mine it was the contact uner the air bag that went bad. It is nothing more then a cylinder that slides into a cylinder with a spring and a contact. With mine the 2 nubs that twist lock it into the bigger cylinder broke off. But do the plates first. One thing you can try is short the plates of the button out with a screwdriver and see if the horn blows. If it does it is for sure the button contacts. 
Melting Slicks
Joined: Feb 2005
Posts: 2,135
Likes: 0
From: Sebastian Florida
St. Jude Donor '06
Just did a search on this for my horn, try this:
Wish I knew who to credit this to, but I don't remember who posted it.
This is a copy of an old post of mine (couple of years ago?) Maybe it will help:
"Apparently horn problems are very common on the C-4 and in particular with the 1990. There have been many posts on the subject over the years.
I will try to walk you through this, but it is being done from memory so please bear with me. What is mentioned here is mainly specific to the 1990 or later C-4. Prior to 1990 a different design was used.
I am assuming that you have checked and cleaned the electrical connections at the horns themselves and checked the fuses.
Many people have reported corrosion in the horns themselves. The cure is either replacement or squirting penetrating oil or WD-40 into the horn. I have never had to try that so I can’t vouch for its effectiveness.
The operation of the horn relay can be checked with 98% reliability by following these steps:
1. Roll down the windows.
2. Turn the ignition “Off�.
3. Exit the car.
4. Lock the doors.
5. Reach in through the window and “Unlock the Door�
6. Attempt to start the car.
If when you try to start the car and the horn goes off, the horn relay is okay. To reset the alarm and to be able to start the car, lock the door with the key and then unlock it with the key. The horn relay is a DPST relay that works either from the horn buttons or the security system.
There are several problems I have found that seem to come up with the horn buttons,
1. The Buttons themselves are made of a plastic that seems to deteriorate over time. This plus the normal (and abnormal) pressing on the buttons causes a little "nipple" inside of them to break. This nipple's purpose is to press down on the brass contacts underneath it and complete the circuit. No nipple = no contact = no horn.
2. There is a wire (one only) that goes between the brass contacts and the hub of the steering wheel. At the end of this wire is attached a plastic spring loaded male bayonet fitting that is inserted into a female socket in the steering wheel hub and twisted into place to hold it. This plastic bayonet fitting and/or its socket will also give up after time and separate causing an intermittent contact or no contact.
Solutions:
1. The horn buttons are available from GM for about $6.95 each. PN
12506007 and 12500608. There are two ways to remove them from the steering wheel.
A. Using a dull thin blade slide it along the hub side of the button feeling carefully for the catch that latches the button to the wheel. There are two on each side-total four, you only have to find and release two on one side of the button.
The top one is about 1/2-3/4' down from the top of the button and the bottom one is about 1/2-3/4" up from the bottom of the button. When you locate each catch, push in (toward the center of the button) gently on it while lifting the button. You have to do this twice-top and bottom on one side. The button should then pop off.
I have mine discretely marked so the catches are easy to find. You may want to do this to them after they are off.
B. The second way means removing the airbag. Disconnect the battery. Pull the fuse controlling the airbag. At the rear of the steering wheel spokes are imbeded two torx screws (size T-27 ). Unscrew these two screws and then GENTLY lift off the airbag. I advise being off to one side of the steering wheel while doing this as an improperly handled airbag can be dangerous. (These things are shipped all over the country without problem but I would rather be cautious). BE SURE THERE IS NO ELECTRICAL POWER AVAILABLE!!!!"
Wish I knew who to credit this to, but I don't remember who posted it.
This is a copy of an old post of mine (couple of years ago?) Maybe it will help:
"Apparently horn problems are very common on the C-4 and in particular with the 1990. There have been many posts on the subject over the years.
I will try to walk you through this, but it is being done from memory so please bear with me. What is mentioned here is mainly specific to the 1990 or later C-4. Prior to 1990 a different design was used.
I am assuming that you have checked and cleaned the electrical connections at the horns themselves and checked the fuses.
Many people have reported corrosion in the horns themselves. The cure is either replacement or squirting penetrating oil or WD-40 into the horn. I have never had to try that so I can’t vouch for its effectiveness.
The operation of the horn relay can be checked with 98% reliability by following these steps:
1. Roll down the windows.
2. Turn the ignition “Off�.
3. Exit the car.
4. Lock the doors.
5. Reach in through the window and “Unlock the Door�
6. Attempt to start the car.
If when you try to start the car and the horn goes off, the horn relay is okay. To reset the alarm and to be able to start the car, lock the door with the key and then unlock it with the key. The horn relay is a DPST relay that works either from the horn buttons or the security system.
There are several problems I have found that seem to come up with the horn buttons,
1. The Buttons themselves are made of a plastic that seems to deteriorate over time. This plus the normal (and abnormal) pressing on the buttons causes a little "nipple" inside of them to break. This nipple's purpose is to press down on the brass contacts underneath it and complete the circuit. No nipple = no contact = no horn.
2. There is a wire (one only) that goes between the brass contacts and the hub of the steering wheel. At the end of this wire is attached a plastic spring loaded male bayonet fitting that is inserted into a female socket in the steering wheel hub and twisted into place to hold it. This plastic bayonet fitting and/or its socket will also give up after time and separate causing an intermittent contact or no contact.
Solutions:
1. The horn buttons are available from GM for about $6.95 each. PN
12506007 and 12500608. There are two ways to remove them from the steering wheel.
A. Using a dull thin blade slide it along the hub side of the button feeling carefully for the catch that latches the button to the wheel. There are two on each side-total four, you only have to find and release two on one side of the button.
The top one is about 1/2-3/4' down from the top of the button and the bottom one is about 1/2-3/4" up from the bottom of the button. When you locate each catch, push in (toward the center of the button) gently on it while lifting the button. You have to do this twice-top and bottom on one side. The button should then pop off.
I have mine discretely marked so the catches are easy to find. You may want to do this to them after they are off.
B. The second way means removing the airbag. Disconnect the battery. Pull the fuse controlling the airbag. At the rear of the steering wheel spokes are imbeded two torx screws (size T-27 ). Unscrew these two screws and then GENTLY lift off the airbag. I advise being off to one side of the steering wheel while doing this as an improperly handled airbag can be dangerous. (These things are shipped all over the country without problem but I would rather be cautious). BE SURE THERE IS NO ELECTRICAL POWER AVAILABLE!!!!"
