I was finishing up the wiring on the Beastt today and just for kicks I junp wired the 58 year old horn under the hood and it actually works so my question is how do you us a 6 vold horn on a 12 volt system, I know it's a dumb question but today I'm brain dead

 

First it's a good idea to replace the horn relay, if you plan on using the horn a lot. Otherwise, it will just draw a little more current in the relay than needed.

If you take the back "dome" off the horn, you'll see a set screw and locking nut. (I'm going by memory) adjusting the screw changes the tone of the horn. With 12v it probably sounds toohigh-pitched. Play with it until it wounds the way you like.

 

A 6V horn will last a very long time on 12 volts. It will be a little louder but really no need to change anything....

 

Thanks Guys, I like the sound so I will just use it as is, Garry

 

You need to put a 12 volt relay on it. The horns will work fine, be louder and will probably have to be tuned - as was previously mentioned.