Head light switch for a '54 converted to 12v

[51504bat]

Getting ready to completely rewire my '54 Ranch Wagon and convert it to 12 volts. I've read conflicting opinions on using the stock '54 6 volt headlight switch vs. using a 12 volt one from a '56/57. From what I can tell the 12 volt switch will accept the knob assembly from the '54 switch and the 12 volt unit will install with no mods where the 6 volt switch was. C&G said the '54 switch should work fine but I'm a little concerned about how the dash light dimmer rheostat in the 6 volt switch will work with 12 volts. Am I worrying about nothing or should I go with the 12 volt switch?

[Rbeck204]

I converted my 1953 Courier to 12v and used the stock switch with no problem. An equal load (watts output for a light bulb, etc.) at 12v is half the amperage of the same load at 6volts. Should be fine.
Rich

[dmsfrr]

The info at the linked page below was written for 6 volt positive ground '55 T-Birds, but virtually all of it will apply to your '54 Ranch Wagon. Don't forget to change the polarity of the wiring to the Ign Coil and clock if it has one. You'll need to add a ballast resistor and a separate 12v Ign Coil power wire from the new starter solenoid.
If the car has an original radio, disconnect the power wire to it.
Unless you go with a 12v alternator, you'll have to re-polarize the generator / electrical system before trying to start the engine. It's very simple and instructions are on the same linked page.

If the existing dash light dimmer circuit leaves the new 12v bulbs too bright you can add a resistor in series with it, or change the switch to a 12v '56 version.
The original 6v headlight switch in my 12v converted '55 has the dash bulbs at a good brightness but, I seldom drive it at night. With all the ambient light in town I wouldn't want them dimmer.

FYI, some '57(+?) headlight switches may use a longer knob shaft or different style knob that doesn't match the '54 version you already have.

https://www.ctci.org/gilsgarage/6to12.php
.

[JeffB2]

Originally Posted by 51504bat

Getting ready to completely rewire my '54 Ranch Wagon and convert it to 12 volts. I've read conflicting opinions on using the stock '54 6 volt headlight switch vs. using a 12 volt one from a '56/57. From what I can tell the 12 volt switch will accept the knob assembly from the '54 switch and the 12 volt unit will install with no mods where the 6 volt switch was. C&G said the '54 switch should work fine but I'm a little concerned about how the dash light dimmer rheostat in the 6 volt switch will work with 12 volts. Am I worrying about nothing or should I go with the 12 volt switch?

Here is a common issue we have run into over the years in the H.A.M.B. 1952-59 Ford Group concerning wiring up the headlight switch when converting to 12 volts. Almost all universal wiring harnesses are "GM friendly" and do not wire up the same as Fords,click on this link and go to Post # 525 to see how to solve it. https://www.jalopyjournal.com/forum/...#post-12641103 Also install headlight relays to lessen the load: http://watsons-streetworks.com/wp-co...rent-topic.pdf If you will be adding any additional circuits for extra accessories add the 70-80 relay to the ignition switch. You can also find these relays and the matching pigtails at Fry's Electronics at good prices. Worked great in my '54

[51504bat]

Thanks all for the good info. I used a universal Rebel wiring kit when I converted my '39 p/u to 12 volts. I used a universal ignition key switch instead of the stock switch and push button along with a Signalstat turn signal unit and all went well with no calls to tech support. The '54 rewire should go with only a minimum of glitches as well with the advice provided here and on the HAMB.

[rotorwrench]

Sponsored Links (Register now to hide all advertisements)

Most switches only care about the amount of current that passes through. With a 12-volt conversion, that is actually an advantage. The original system would already be made to take more current than the 12-volt system will require. With 12-volt, you can use a full 2 AWG numbers smaller wire just as long as you know what gauge they original were. An example would be that a 16 gauge wire can be replaced with an 18 gauge wire in the same circuit. Fuses can be lower amperage as well since they are rated to protect the wire in most all cases.

Clocks may be polarity sensitive depending on how the movement is designed. Radios with the old style vibrator coils are not polarity sensitive but the ones with a solid state type vibrator are. Amp meters that are the induction type will require the wire be passed through the loop in an opposite direction to give a proper indication. Changing bulbs will be required throughout.

[paul2748]

I am using the stock switch on my 54 which has been converted to 12 V. Been that way for up to 20 years with no problems.

[19Fordy]

Use a relays and the original switch. Relay will take the load off the switch. I am petty sure you can run the relay thru your dimmer switch. Peruse all of this.
https://www.google.com/search?q=how+...hrome&ie=UTF-8

[dmsfrr]

Originally Posted by 19Fordy

Use a relays and the original switch. Relay will take the load off the switch. I am petty sure you can run the relay thru your dimmer switch. Peruse all of this.

19Fordy, the problem stated in 51504bat's first post isn't an excess load that the switch can't handle. With the voltage going from 6 to 12 the current/amps/load on the switch is cut almost in half.

His concern with the dash light dimmer is actually not enough current load to dim the dash lights the same as before.

[rotorwrench]

A person could run a dash light dimmer off of a separate rheostat more in tune with 12-volts if it doesn't work with the OEM dimmer rheostat in the switch.

[Daves55Sedan]

In agreement with dmsfrr's post, here is an electricians rule of thumb for you:
The lower the voltage is, the greater the amperage is, therefore the higher the voltage is, the lesser the amperage is.
Going from 6 volts to 12 volts will DECREASE the ampere load by about one half.
That is why it is not necessary to change wiring sizes in 6 to 12 volt conversions. Your existing wire will now be quite well oversized to carry the same loads with a higher voltage.
Why did auto manufacturers change the electrical system in 1956 to 12 volts ? because it saved $$$ in tons of copper wire, since now all the 12 gage wire can now be 14 gage and all the 14 gage can now be 16 gage. Multiplied by 100's of thousands of cars per year.
Industrial trucks and machinery using 24 volt electrical systems don't have a nickels worth of wire in them.

[bobss396]

I have a Kwik Wire harness in my '59, I bought their HL switch and dimmer switch at the same time, just so I know they would be compatible. See if Rebel offers one. Rebel has a good thread going over on the main HAMB board.

[Dragginsteel]

I am planning to convert my 6v 41 Ford business coupe to 12 v. Have a question about my headlight switch. Standard headlight switch has 5 terminals 1 terminal comes off the proprietary fuse block (it's fused) this one works the headlights and the dash lights. I have a second unfused wire off the power side of the fuse block (heavy yellow) to the switch, this appears to power the tail light and parking lights. I am converting headlights and taillight to 12 v lamps, hoping to leave the dash lamp and parking at 6v by reducing the power with a reducer ( a separate reducer on the other fuse for the gauges) I don't run a windshield motor of a heater fan.

My question why does the damn headlight switch have two power sources?
Should I just get a new headlamp switch with one power source change all my bulbs or can my headlamp switch have a 6v and a 12 v in??

[dmsfrr]

Originally Posted by Dragginsteel

I am planning to convert my 6v 41 Ford business coupe to 12 v. Have a question about my headlight switch. Standard headlight switch has 5 terminals 1 terminal comes off the proprietary fuse block (it's fused) this one works the headlights and the dash lights. I have a second unfused wire off the power side of the fuse block (heavy yellow) to the switch, this appears to power the tail light and parking lights. I am converting headlights and taillight to 12 v lamps, hoping to leave the dash lamp and parking at 6v by reducing the power with a reducer ( a separate reducer on the other fuse for the gauges) I don't run a windshield motor of a heater fan.

My question why does the damn headlight switch have two power sources?
Should I just get a new headlamp switch with one power source change all my bulbs or can my headlamp switch have a 6v and a 12 v in??

Dragginsteel,
Without being able to see the headlight switch and wiring setup you have...
If it's original wiring the insulation has likely failed in enough places it should all be replaced.

I suspect converting part of the car to 12v while leaving other parts 6v could be a recipe for a very watery visit from your local fire department, along with subsequent phone calls to various insurance companies.

By the way, you should have started a new thread for your questions, not tagged on to an older one.
A question about a '41 Ford business coupe is more applicable to the Early V8 (1932-53) forum.
And more likely to get a relevant answer sooner.

.

[fordor41]

I rewired our '41 ford to 12V and used the stock H/L sw with no problems. lasted all 25 yrs we had the car. even had halogen headlights.