When I beep my horn the dash starts smokin'

[readyman]

What's the failure rate of 27 year old horns? Do they usually go dead short or am I just lucky?

and I thought someone just forgot to plug the connector on the horn...

 

[Barrman]

Check the ground on the bracket for the parking brake. That ground controls just about everything under the dash in some form or other.

Can you hear the horn relay clicking when you push the button?

If all that checks out, put a test light in the horn wire at the horn and see if power is getting there. Don't forget that the black out light switch also controls the horn so wires go through there.

Of course, the TM troubleshooting section in the -20 walks you through this step by step too.

I have a 1984 Suburban with a bad horn unit by the way. So, they do fail.

 

[Warthog]

And don't forget that there is a diode on the back of the horn relay that is know to go bad. It will cause the horn to stay on all the time.