the type of horn you're thinking [like this, "Klaxon"] was aftermarket and primarly found on 20's & 30's Fords, 6 volt - no doubt there are Klaxon repros around in 12V, but current draw would be unique to the particular item you have .... always a good idea to use a relay for a horn regardless

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics