The Ford Barn - View Single Post - Horns

drolston · 11-10-2016, 01:13 PM

A degree in electrical engineering proved to be of no help in the attempt to convert my '41 horns to 12 volts. Tried a range of high wattage resistors in series; tried a wound voltage tap resistor; tried a MSD DC/DC voltage reducer that worked on windshield wiper and heater motors. Nothing worked; mostly no sound. At the heart of the problem is the fact that you have an inductive coil that also presents a series resistance in a circuit that the make/break points cause to behave more like an alternating current circuit.

I just left mine on 12 volts. Sounds more like a freight train than a '41 Ford, but it gets the desired effect in traffic.

Someday I will get out the EE 201 text book and figure out what combination of resistor, capacitor and coil is needed to get the horns to behave as original.

11-10-2016, 01:13 PM	#37
drolston Senior Member Join Date: Jun 2014 Location: Williamsburg, VA Posts: 1,811	Re: Horns - 6 to 12 volt A degree in electrical engineering proved to be of no help in the attempt to convert my '41 horns to 12 volts. Tried a range of high wattage resistors in series; tried a wound voltage tap resistor; tried a MSD DC/DC voltage reducer that worked on windshield wiper and heater motors. Nothing worked; mostly no sound. At the heart of the problem is the fact that you have an inductive coil that also presents a series resistance in a circuit that the make/break points cause to behave more like an alternating current circuit. I just left mine on 12 volts. Sounds more like a freight train than a '41 Ford, but it gets the desired effect in traffic. Someday I will get out the EE 201 text book and figure out what combination of resistor, capacitor and coil is needed to get the horns to behave as original.