I'm converting a 55 to 12 volt and am wondering about the ignition switch.Did you guys that have done this changed the ignition switch to a 56 or just left the 55 switch in there?



Thanks!

 

Paul,

Boonville,MO

Paul:

There is no need to replace the ignition switch.

John - "The Hoosier Hurricane"

Thanks John......That's what I thought,but wasn't sure.It's been about 50 years since I did one of these.

 

Paul,

Boonville,MO

John, what about the headlight switch? I have read that some say the the instrument light dimmer rheostat needs to be changed and others say it doesn't. Swapping switches (if necessary) would be easier than swapping rheostats I would think. What do you think. Thanks

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

The reostat can be removed and dash lights run undimmed.

  

Or you can leave the headlight switch alone and it will work fine, mine has for years. All switches are rated for the amps at 6 volts which is almost x2 what you will have at 12V. You need to change all bulbs. If you are using points you could change the starter solinoid so that it will start on 12V and then run the coil through the resistor, this needs a new wire from the solinoid to the coil. Or you could keep the same solinoid and run the resistor at all times including starting. Keeping the radio and the blower original can be done with a big resistor that used to be sold as a "Volt-a-Drop". The radio and blower do not care about polarity. All the wires are sized for 6V and so the amp loading is generally 1/2 of the twelve volt current. FoMoCo did not change wire size for most of the harness from '55 to '56 even the color codes are the same. The main cables from the bat to ground and to the solinoid are smaller on 12V cars so your '55 cables will be fine. I have also run starters, power seats, and overdrives that were for 6V on 12V without problems. Convertible top motors will also probably be OK but I have not done that. If you are going to replace it anyhow you might see if it lasts as long as my stuff has but you do need to attend to bulbs, radio and heater blower.

Doug T

The Highlands, Louisville, Ky.

If you try to use the resistor in the starting circuit instead of having a bypass wire from the solenoid the resistor may go up in smoke.Happened to me many years ago when I converted from 6 to 12 not being aware a bypass circuit was required.Couldnt figure out what happened until another learned person explained it to me. 

  

I used all the original switches in my 55 when I converted to 12 volts,used a IVR for the gauges and replaced the horns and heater motor with 56 parts.

Butchering up everything I can get my hands on in Dayton Ohio

Where can I get the Big Resistor/voltage drop or how do I specify for it. Do you need one for the radio and one for the heater blower or will one do.



Horns: Are they ok on 12 volt?

As far as the radio-any shop that repairs/services vintage radios sould have what you need.Heater motor- either get one for a 56 or run yours until it quits and than get one from a 56.How often do you use your heater anyway?