My 1938 Buick horn was working fine until I was cleaning the horn ring and the horn went off and would not stop.
I was able to disconnect the wires to the horns after finding a screw driver (about 5 minutes) and they stopped.
The next day my battery was dead as a door nail. Absolutely nothing. I recharged the battery last night and the lights worked, blinkers worked with the appropriate voltage drop showing on the dashboard gauge. No other drop or drain showing on the gauge. The battery was completely dead again this morning. It is a fairly new battery.