It looks like the P.O. forgot (or didn't bother) to reduce the voltage going to the horn when he switched the electrical system to 12 volts. When I opened it up it smelled like a camp fire and all of the insulation was melted off the wires.

I'm putting everything back to 6 volts so I had to find a replacement. In the picture the original horn motor is on top, the replacement I found on Ford Barn on the bottom.

 

When I opened mine up this is what I found.

Strange scratches all over, it doesn't work either. Sorry the pic is so big.

 

Looks like you are good to go now. Previous owners and 12V conversions...

 

Looks like someone tried to scrape the rust off the diaphragm. My new one has some light surface rust on the outside exposed to the weather but the inside looks almost new.

 

1948/55 Truck & 1949/55 Ford Passenger Cars:

B5A-13832-C .. 6V High Pitch Horn / Obsolete

No Ford dealer or obsolete parts vendor has any.
-------------------------------------------------------
B5A-13833-C .. 6V Low Pitch Horn / Obsolete

NOS PARTS LTD in Waxahachie TX has 1 = 972-937-2201.

 

So here's a question about the horns then... If they are 6V specific, what would you be using to reduce it from 12V? They are fairly high current if they need a relay, an none of the voltage reducers I've seen would handle that type of current.

 

Has anyone had luck repairing the inner wiring of one of these horns? I've got a marvelous old dual trumpet style just aching to make noise again.

 

I'm pretty ignorant when it comes to electrical issues so I can't answer your question about how to reduce the voltage. However, it's my understanding that the earlier horns (48-50) do not use a relay.

 

Scroll down to basic part number 13853 / FAA-13853-A is 6V

C = F1/F100 / D = F2/F250 / J = F3 Parcel Delivery/P350 / JH = F5 Parcel Delivery/P500 / Y = F3/F350 / T = F5/F500 / TH = F6/F600 / TL = F4 / W= F5 COE/C500 / WH = F6 COE/C600

The rest of these parts catalog symbols I have to look up to decode 'em, but I'm not gonna bother.

 

As I said, I'm pretty ignorant about this stuff. Where is the relay located? A picture would help.

 

Parts catalog illustration of the wiring doesn't show the 1948/50 location of the horn relay. Text section sez it's the same 1948/55 6V

 

In the shop manual I have it says under "Horns" that the deluxe models have two horns that are controlled by a relay. I guess I concluded from that that the standard model, with a single horn mounted behind the driver's headlight, did not use a relay. Hopefully someone can clarify this for me.

 

There isn't any horn relay as part of the 48-50 stock wiring for trucks.

 

FortyNiner - thanks for confirming that there isn't a relay on the earlier trucks.