using a 12 volt system with the 6 volt horn

[briphaeton]

What I use is a Ohmite RESISTOR, 2 OHM, 100 WATT, ADJ TUBULAR, WIREWOUND, +-10% TOLERANCE.The Galco part number is D100K2ro.
It is a adjustable resister so you get adjust what sound you want from your horn. I found it in a old Restorer article? You have to make a simple bracket that mount on the inside frame rail so it's out of sight. Works great.