1990 Vette convertible, horn works when security is set off, but to try the horn on the steering wheel, it won't work on either side. Manual doesn't list a fuse for it...wondering where the horn relay is? Or if anyones knows what else to check.

 

Try posting in the C4 Tech/Preformance section to get your questions answered. This section is really for help with forum issues or problems.

 

try checking the horn switches themselves, or where the horn switch harness "plugs in" to the steering column. you will need to pull the airbag to check both of these items. i just responded to a post containing some info on disabling the airbag:

http://forums.corvetteforum.com/showthread.php?t=859974

i'm pretty sure there is a fuse for the horn. perhaps it is under something like "security". if the horns work with the alarm i don't think it is a bad relay.

 

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!!!!"

 

I had the same thing go out on my 87' the relay is behind the information sensor. Its either the relay or the fuse behind there. Check to see if the fuse is burnt it is marked security and is near the relay.

 

I meant to say information center (where check engine etc. light up)

 

same thing happened. the piece of metal that make contact with the wires for the horn wore out. try this first.
pull the fuse for the air bag just to be safe.
take a small flat thin screw drive and pull the grey buttom off
take the wire that was connected to the button off and touch it to the round piece of metal (ground)
if the horn sounds then it's the button.
this was the mod I made
http://www.geocities.com/valdeze@sbcglobal.net/DV2.html

 

I have the same car and the same thing just happened to me! Any suggestions? I've already checked all fuses, including the four under the dash and there all good.

 

The previous moron who owned the car hacked it so that he could stick a buzzer button to directly power the horns. He has taken the buttons off and there is nothing behind them. I can't seem to get replacement switches from GM for the horn. Just the buttons or the whole wheel. Any suggestions?