need help on my 86 horns dont work have tested them they r ok but when i push the horn button security lite comes on any advice or help would be appreciated

 

Had that happen on mine. Turned out the horns themselves were oxidized and wouldn't sound off when a short burst was given to them, but would work fine when I used them normally from the wheel. I replaced the horns and all is well.

May not be your situation, but that's my 2 cents.

 

Is the horn relay OK ??

http://members.shaw.ca/agent86/Horn%20Electrical.pdf




http://members.shaw.ca/dankai/Vats%20Electrical.pdf

 

Obviously, you should check the horn fuse first. You didn't mention if the alarm system works. You mentioned you tested the horns, I assume you applied 12 volts directly to them to test them. You can test the alarm system and relay by opening the door, rolling the windows down, locking the doors with the power door locks, close the door, then reach in and manually unlock the door and open it. This should cause the alarm to activiate and pulse the horns on and off. Hopefully it works, If it doesn't then it could be the relay or the alarm system. You can also check the relay by removing the horn cap and checking the horn wire and contact wire. Try grounding the horn cap yellow wire to see if the horn honks. If it doesn't then I'd go after the horn relay. Removing the radio trim plate to access the horn relay is the only way to get to it. Before buying a new relay, you can do some metering at the relay connector by unplugging the relay. Check for 12 volts at the pink wire. If no power then check for continuity between the fuse and the pink wire at the relay connector. If that's good then jumper the pink wire to the green wire. This bypasses the relay and applies 12 volts directly to the horns. If this doesn't work, you could have an open between the relay and the horns. Check for continuity between the green wire of the relay connector and the green wire at the horns. If it's good then you may have an open on the black wire from the relay connector to the steering column. Try grounding the black wire with the relay plugged in and see if the horn works. If it does then your problem is on the black wire circuit to the horn button. You could also have a open on the black wire from the relay to the horn slip ring contact or the slip ring contact and or the spring wire in the horn area is bad or open. As you can see the only way to fix this is to test with a meter for voltage and continuity before going out and buying a new relay. But for what it costs it may be less time consuming to just buy a new relay. But I hate throwing money at the car since this what everyone dreads. Anyway, good luck.

Art

 

You will have to pull the steering wheel but the connector "stack" plastic piece under the lock ring could be broken, very common issue on GM columns, under $10 for the replacement part