[W126 Coupe] Horns not working

[Ernie Stephens]

My horns stopped working. At the same time, I have a warning light on my dash that an electrical device (light bulb,etc) is malfunctioning.  I checked my fuse and it appears to be in good shape.  I suspect that there is a horn relay somewhere in the circuit but I don't have a wiring diagram; can anyone tell me what and where I should be looking for?

Thanks,
Ernie