I found a set of horns on EBay - they said they are from a 50's school bus, who really knows, but I got 'em.

I put a 12V battery on them for a sec. One hummed and the other made no sound.

How can I determine if they are 6V or 12V? How do I go about testing these?

Dual horns

Bob

1954 Chevy 3100 5-Window
1954 5-Window COE aka "THE BEAST"
Bill Ritchie's Original Truck

Granddad's Hardware Store: Ritchie Hardware, Concord, N.C.
Bethesda, MD