Old electric truck horn-need wiring help

[Guest jeremyb]

HI I have an unusual question here. I am not a vintage car owner (YET) but I do love old things.

THe other day I an old truck horn, black tin, about 24 inches long with a heavy bulbous end to it. It has two electric connectors across the top and one at the bottom. I would like to hook this up and use it on my vintage style bike for a festival coming up. Any knowledge on how to wire it up and get it working? My old mechanic said it was probably 6 volt. there are no stampings anywhere. It looks to me to be from around the 1930's-1940s.

Cheers

Jeremy (liker of old things)

[DAVE A]

Jeremy;

I would take the advice and try 6 volt first. I'm not sure what damage would occurr if it is 6 volt and you use 12 but I would try 6 first. Test with direct connections to be sure it works before installing it. Normally the 2 threaded terminals you see are the electrical connections. 1 goes to the hot side and one to the ground. Again, it normally doesn't matter which is which. From the battery + terminal to one side and from the battery - terminal to the other. Put a switch in the middle of one wire and you are in business.

[ply33]

Not sure about your meaning of "top" versus "bottom" but the two threaded fasteners shown on the top of your second photo are for mounting the horn on the vehicle. They are not electrical connections.

The electrical connections will probably be screws through some insulated bushings on the back side of the horn.

There may also be a set screw with a lock nut on it (might be under the cover depending on manufacturer and model of horn). That will be an adjusting screw. And you probably don't want to play with it. On many horns that is quite sensitive and a 1/8 of a turn will take you in to a non-functional state.

[Bhigdog]

The two bolts/screws in the pix are mounting bolts not electrical connections, per se, however either one can be used as the ground connection. Find an insulated screw or screw hole on the "bulbous" can. That is the other connection point. There is a good chance your horn will not work because the points are corroded. That's usually repairable. Be advised that the horn when working is a real current hog. You will need a hefty battery to power it. A few flashlight batteries won't cut it.............Bob