6 volt to 12 volt conversion
 

I would like to convert my 6 volt system in my 1949 F1 pickup to 12 volt. Do I have to buy the $419 kit to change over everything or can I replace just a few items since some say my starter will handle a 12 volt battery. I have a 6 volt heater and also 6 volt dash lights/insruments. I am sure I have to replace the bulbs in my headlights/tailights and old generator.

Please advise as to cost and where to buy all of these items

Thanks,
Rod

Re: 6 volt to 12 volt conversion
 

Have you tried the search function? Lots of info.

Re: 6 volt to 12 volt conversion
 

Don't forget to change your turn signal flasher.

A previous owner had converted my '36 to 12 volt, changed all the bulbs. Could not figure out why the aftermarket turn signals would not work. pulled the flasher, it said 6 volt on it.

Trip to the auto parts store, boy are they dumb now adays. "What car is it for?" I said I just need an aftermarket flasher, But for what car. If I tell you, you wont have it. But what car. OK, 1936 Ford with aftermarket flashers. Oh, we don't have that. Ya, I know. Do you have an aftermarket one. I don't know, you can go look on the wall. Yippi, yes they had one, but not because they knew they had it. Damn Kids!

Re: 6 volt to 12 volt conversion
 

You pretty much know what you have to do.
The voltage drop to the gauges can be handled by one post 1955 Ford voltage drop unit.
The heater motor will run on 12 volts (just faster).
If you have a radio there are two factors to consider, voltage drop and polarity.

Re: 6 volt to 12 volt conversion
 

Generator/ alt

Re: 6 volt to 12 volt conversion
 

Been done thousands of times.
- Change all bulbs to their 12 volt equivalent. Find a conversion table on line.
- Install Runtz step down converters for all of the dash instruments. All of the old Ford parts companies carry them. $20 each at Speedway; probably need three.
- You can use your 6 volt starter but if you ever have to crank a long time, it may spit out some solder and fail. I recommend converting by buying a 12v starter for a FE series Ford engine (around 1963; maybe $55) and use the housing with field coils on the armature and end plates of your existing starter. Be sure to use the little brace that goes from the starter housing to an oil pan bolt.
- I assume you are mounting a 12V alternator. The power wire from the generator becomes the power connection on the alternator. At the regulator you just add the Generator (now alternator) wire to the Battery terminal. The regulator becomes just a convenient junction point. The wire that hooked to the old generator field terminal can be removed or used to ground the alternator case by taking the field wire at the regulator off of the field connection and hooking it to ground.
- I converted heater motor and windshield wiper motors to 6 volts by using CPT voltage converters, but other brands are available. Needs to be rated at 7 amps or 42 watts.
- The horn will work but sound different. I have tried resistors and other step down converters, but nothing that works on the vibrator horns. You should change the horn relay to 12 volts; easy switch.

Re: 6 volt to 12 volt conversion
 

you can go to Gil's garage at the CTCI Thunderbird web site. There is an article regarding conversion of '55 birds to 12V.
https://www.ctci.org/gilsgarage/6to12.php

Re: 6 volt to 12 volt conversion
 

Best info: http://www.ebay.com/gds/6-to-12-Volt...1571127/g.html You should find this handy also,see post # 2 https://www.ford-trucks.com/forums/1...volt-bulb.html

Re: 6 volt to 12 volt conversion
 

Didn't look at the links posted above, but you need to get the coil straightened out. With 12v neg ground, the + side of the coil goes to the ignition switch and the - side goes to the distributor. Need a 12v coil that has the proper internal resistance or a coil and a ballast resistor. What you need to end up with is around 6 ohms, either a 6 ohm coil or a 3 ohm coil with a 3 ohm ballast resistor.

Re: 6 volt to 12 volt conversion
 

When I changed mine over to 12 volts I chose a 12 volt alternator with built in regulator and eliminated the regulator all together. Also went with a Petronics electronic dist kit and the proper 1.5 ohm coil. Since then I changed to a "Bubba's" GM dist which I like much better. Voltage drop for original gauges and change out of bulbs to 12 volts. I used the original 6 volt starter for many years before going with a 12 volt one.
I still have the original dist with Petronics unit in it in my " box of "stuff" if you want to go that way. Believe it needs a new cap . PM me if interested. Chap

Re: 6 volt to 12 volt conversion
 

I thought it was 3 ohms...either by a 3 ohm ballast resisted fitted coil or a 1.5ohm coil with a seperate 1.5 ohm ballast resistor?

Please clarify as Im in the process of doing this at present on my 36,

Thanks.

Re: 6 volt to 12 volt conversion
 

Corrected the ohms!!!

Re: 6 volt to 12 volt conversion
 

Double post!

Re: 6 volt to 12 volt conversion
 

You are correct, must have been half asleep on that post! or maybe completely asleep. :)

Re: 6 volt to 12 volt conversion
 

Has anyone tried putting the Speedway Windshield Wiper Convervsion Kit (vacuum to electric) on a 47 Ford Super Deluxe? I thought I read somewhere that someone tried and had a lot of problems and finally bought a Honda electric motor from a scrap yard.

Re: 6 volt to 12 volt conversion
 

Lots of good info here. There's folks that will tell you that you can use the 6V starter. no problem, been doing it for 20 years!

There's those that say you have a good chance of breaking the Bendix starter spring from extra force if you do.

My Bendix spring broke.....

I replaced it with the new style of Bendix drive that (apparently) doesn't break. Fingers crossed.

Re: 6 volt to 12 volt conversion
 

I found the 12v conversion guide from Vintage Auto Garage to be quite helpful.

https://vintageautogarage.com/?gad_source=1&gclid=CjwKCAiAh6y9BhBREiwApBLHC3MGR0 bg_RWNB-ZzDcU1w9QKAh2m4UpESJOdy_6ETvv24JeCtM1KHRoCvtEQAvD_ BwE[/IMG]

Re: 6 volt to 12 volt conversion
 

I used the Newport Engineering Kit in my 48. I did it quite a few years ago, so I don;t remember any problems installing. But it is a 12 volt setup.

Re: 6 volt to 12 volt conversion
 

Gotta ask, why change to 12 volts??

Re: 6 volt to 12 volt conversion
 

Ken, your question is remarkable ...Not the question itself, but the fact that it took 7 years and 19 posts for someone to ask it.

Re: 6 volt to 12 volt conversion
 

They just did a full segment on 6volt poss ground to 12 volt neg ground on Iorn trap garage on youtube. Tim

Re: 6 volt to 12 volt conversion
 

Why change ? Good question. For those who want to keep their car all-original or concourse worthy, keep it 6 volts. Although 6 volt generators and starter motors can be repaired there are those who may be concerned that 6 volt batteries. light bulbs and sealed-beams will not be available at some point. Some NOS items will be exhausted. As it is now, some foreign made items tend to be of lower quality. And just like using 240 volts adds an uummmff to a 120 volt electric motor, for what its little worth upping the voltage from 6 to 12 volt has an effect.

Re: 6 volt to 12 volt conversion
 

Re: 6 volt to 12 volt conversion
 

Ken, I'm with you. It worked when it was new. What's wrong with your system that is doesn't work now?


When I bought my '41 business coupe 3 years ago it didn't run worth a cr@9, a 12 volt conversion was my first project. After researching it, I decided instead to fix the real problems: 1. found that there was a missing ground strap from the firewall to the engine. That eliminated 40% of the hard start issues. 2. went into distributor timing and adjusted it to spec. That was another 30%. 3. Bought a high quality Skip Haney coil and Tubman condenser. Awesome! There's the remaining 30%. It now fires up as quickly as my brand new fuel-injected, computer-controlled Japanese car.

Re: 6 volt to 12 volt conversion
 

When I built my 34 jalopy 10 years ago, I went 12 volts. 3 reasons-
1, I wanted a modern radio, hidden out of sight, or a conversion of a real 34 radio=expensive.

2, I wanted a cig lighter port to charge gps and phone.

3, it seems I am often flip flopping batteries around to get something dead running, and 12 v is common in the fleet.

Truth is, I have never plugged anything into the lighter port.
I never did install a radio-dual straight pipes is music enough. And I think I have changed out the battery once in 10 years. Yeah, it spins over good and runs perfect with the proper ballast resistor figgerd out by Bubba (RIP) , but my 6 volt fleet runs just fine too. Model A's that start and drive in winter, temps down to 10 or 20 and I still drive em, snow or not.

Re: 6 volt to 12 volt conversion
 

From http://www.how-to-build-hotrods.com/6v-to-12v.html

A 6v to 12v Conversion to Improve Your Car!

Changing over from 6v to 12v is one of the easier and cheaper projects to update an old car or truck. The benefits are easier starting and greatly improved headlights, as well as the ability to add 12v accessories.

However, before we get into this project, look over your wiring.

If your wiring is frayed, split, or cracked, start over. There is no sense putting all this work into changing over if you're still going to get shorts and take a chance on burning down the car. It's easier and cheaper to do it all once than to change over, fight bad wiring, have problems, then have to do it all over a second time...

Ok, let's get started...

First, if you're wiring and your switches are in good shape, then so are you!

A 6v wiring system and switches are more than enough to handle 12v. It's heavier because it has to carry more amperage. Less volts means more amperage. Changing to 12v cuts the amperage load approximately in half. So, the wiring will live happily with 12v.

Second, figure out if you have a positive or negative ground.

You will be going to a negative ground. So, if you have a positive ground, you need to do a few things first.

Start be reversing the power wires to anything that is polarity conscious. Things like the ignition coil, amp guage, wiper motor, heater motor, etc.

Also the battery cables will need to be changed or modified. The ground strap will need to reach and have the correct end to connect to the negative post and the cable to the starter solenoid will need to reach and have the correct end to connect to the positive post of the new battery.

Now, let's focus on the areas that you need to change.

Starter

The starter is usually the easiest area to deal with. 6V starters are just fine dealing with 12v and will last a long time.

You will need to change the starting solenoid over to a 12v solenoid. 6v solenoids will work if you need to start in an emergency, but will burn out quickly and could lock the starter on or cause a fire.

Usually 6v positive ground starters work just fine being switched over to 12v negative ground. Just change the cable to the positive battery terminal. However, you might find some models won't work and in that case take it to an auto electrical shop and have the motor leads reversed if you can't find a negative ground starter that will interchange. This is rare however.

Charging System

The first thing you need to do is get a 12v battery of course. Take your battery box measurements and get a battery that will work for your application. Also make sure you have clearance above if you use a top post.

Now you have the option to either switch to a 12v generator or a 12v alternator.

A generator isn't used as often, but it is simple to change out. The brackets are usually the same and wiring stays the same. You will have to change out the voltage regulator for a 12v one also.

Most choose to go with a 12v alternator. More specifically, most use a General Motors 10SI alternator. They're tough, small, and cheap, and most places have them in stock. They're also easy to wire in. They also do away with the stock voltage regulator as they already have an internal regulator. More info here: 10SI alternator info

They're not that hard to install as many brackets can be made or modified to install it. Many older 6 and 8 cylinder engines have brackets available that will work because later in life they switched to alternators. There are lots of aftermarket brackets available also. Check in any good hotrod or streetrod magazine for suppliers of brackets. Get creative!

To wire it in, unhook the wires from the voltage regulator, cut the ends and seal them off and tie them out of the way with the rest of the harness. Or you can remove them.

Now, using a 10 gauge wire, run from the Bat terminal on the alternator to the positive cable end on the starter. Or, if you have an ammeter in the dash, run from the alternator to it and then to the starter. Remember, you have to switch the leads on the ammeter if you're changing from positive ground to negative ground or it will read backwards.

Hook up another short 10 guage wire from the #2 pin on the alternator to the Bat terminal on the alternator. The #2 pin is the one farthest away from the Bat terminal. (You can get the plug for the 10SI alternator with the 2 wires from any auto parts store.)

Now hook up a 16 guage wire from the #1 pin on the alternator to an idiot light (a small light you can get from the auto parts store to put on the dash with 2 wires coming off of it.) Neither wire of the light goes to ground. Connect one wire to the 16 guage wire from the alternator, and the other to the ignition switch. Otherwise your engine may keep running after you shut it off. Now that's taken care of...

Ignition

Your ignition system needs to be in good working order first. Plugs, plug wires, distributor cap and rotor, etc.

The first thing you want to deal with is the coil.

If you are 6v negative ground going to 12v negative, you can leave the wiring to the coil alone. If you are 6v positive ground going to 12v negative, you need to switch the two wires on the coil. Negative to positive, positive to negative. For a 12v negative system, the ignition switch wire goes to the + terminal on the coil. The wire from the distributor to the coil goes to the - terminal on the coil.

If you aren't going to use the car much and just drive it easy, you can get by with the old coil. You just have to add a ballast resistor to drop the voltage back down to 6v for the coil. We'll cover that in a minute.

If you are going to drive the car more and have some fun with it, switch to a 12v coil. They don't cost that much and are really recommended. They have more windings and live much better in a 12v environment. Some stock 12v coils need a ballast resistor and some don't. Here's some parts numbers for you:

-AC Delco part # U515
This is a universal 12v coil that DOES NOT need a ballast resistor.

-AC Delco part # U505
This is a universal 12v coil that NEEDS a ballast resistor.

Where would I put a ballast resistor?

You put it in the wire from the ignition switch to the coil. You want to mount it away from other wires or anything flammable as it will get hot. Normally you mount it on the firewall above the engine. Just cut the wire, add connectors and hook one wire to one prong of the ballast resistor and one to the other.

Here's some ballast resistor parts numbers for you:

-AC Delco part # C1101
This is a single ballast resistor with a mounting bracket.

-Napa part # ICR-13 (Echlin)
This is also a good firewall mounted ballast resistor.

How about the points?

The 6v points will be just fine and are usually just a little tougher than the 12v points.

Now for the condensor.

You need to change it. Any late model condensor will work. All you really have to worry about are the mounting and the ends.

Here are some condensor part numbers for you:

-AC Delco part # A202Z
This is open lug with side mounting bracket.

-AC Delco part # E211
This is a closed lug with a rear mounting bracket.

-AC Delco part # F204Z
This is open lug with a rear mounting bracket.

Tip: If you have any trouble at the parts store on these ignition parts or they want a car, just go with late sixties - early seventies Chrysler products. They work very well.

Gauges

Let's make those guages work.

First, all the bulbs in the guages and guage clusters as well as any other bulbs in the dash or interior need to be changed over to 12v. Just take the old ones in and match them up to 12v bulbs.

If your guages are mechanical, they're fine. If they are electrical, they need a ballast resistor to make them work. If you have idiot lights, you just change the bulbs.

The amp guage will be fine. However, if going from positive ground to negative ground you just need to switch the wires side to side or it will read backwards.

Some fuel guages work just fine on 12v while others don't. You won't blow it up, but if it doesn't read right after switching over to 12v, it probably will need to be run through a ballast resistor. Just put it in the power feed to the gauge.

The rest of the guages will need a ballast resistor of some kind wired into the power input of the guages.

Heres some possible part numbers for ballast resistors for your guages. Look them up and see what will work best for your needs:

-AC Delco part # U1745
This is what it says: "Voltage reducer. Reduces 12 volts to 6 volts. 1.5 ohm resistance for 4 amp maximum load. Permits use of regular 6 volt accessories on 12 volt systems. Mounts through 7/16" diameter hole. Includes clamp on bracket."

-AC Delco part # F610 and F611

-Napa part # VT6187 (Echlin)
This may be the best option. One unit can feed all your seperate guages. Just run a wire from the ignition switch to the unit and another wire from the other side of the unit to one guage then jump wire to the next guage and so on.

Remember to mount these ballast resistors where they won't melt any wires or catch anything on fire as they will get warm or hot.

If you don't want to mess with the original guages, have a rats nest of bad wiring under the dash, or after a quick and easy way to wire up guages the aftermarket is the way to go. Just go with aftermarket guages and sending units. It's often easier and you know they will work.

Don't forget the radio. About the only way to convert your radio is take it to an automotive radio repair shop. If you can find one. Probably the best bet is to find one on the internet and send it out. However, it's probably gonna cost ya. Ballast resistors really don't work on radios as they are very specific about power. Replacing with a new system is usually the cheapest.

However, if you want to retain the looks of your radio, a lot of people leave it in and hide a newer radio somewhere within reach. Or, look in hotrod or streetrod magazines as there are aftermarket options that mimic the look of your old radio or actually work through your existing radio.

Blower Motors and Wiper Motors

These 6v electric motors won't last long on 12v. They can be made to work usually with a heavy load ballast resistor. However, it may be easier and sometimes less expensive to just change the motors out for 12v ones.

If you want to use heavy load ballast resistors try this part number:

-Napa part # VT6187 (Echlin)

Now then, on to the lights.

Lighting System

This usually is fairly simple.

You DO NOT need to switch your headlight switch, the brake light switch, headlight high beam switch, the headlight circuit fuse and the turn signal fuse. They are just fine for a 12v system.

You will want to change your turn signal flasher for a 12v unit. Just take the old 6v one in and match up a 12v replacement. The wires connect to the similarly labeled terminals on the 12 volt flasher.

Now just change out the bulbs. Look closely at the sockets and make sure they are clean and not corroded. Usually you can just take one of each type of 6v bulb you have and find its 12v equivalent. You want to pay attention how the base is made and the size of the bulb. Sometimes you may have to change out the pigtails in a socket to make them work. Pigtails are the bottom terminals that push into a socket and have the wire ends. Or you may just change the entire socket.

Ok, now that's done...

Now for some final things you might need to look at...

Do you have any relays? Some older vehicles have them and you need to change them to 12v versions. Look through your wiring. Things like horns might have them. You may not have any at all.

Look at your ground straps!

Almost all electrical problems can be traced to bad grounds. Some really weird and seemingly unrelated stuff can happen if you have bad grounds.

You can never have enough ground straps. Especially if you start adding accessories. You should have a cable from the negative post on the battery to the engine block, a strap from the engine to the firewall, a strap from the dash to the body isn't a bad idea, a strap from the body to the frame or the battery negative post, and a strap from the frame to the engine block. It sounds like a lot, but if you start looking through your car, you probably have most of them already. Make sure your grounds have clean connections and aren't in bad shape. If you're unsure, just put on another one. It's cheap insurance.

And finally...

When you do your electrical work, be neat. It makes things so much easier to work on in the future and looks professional. Remember, you're building skills here... Take pride in your work. Use good materials, stick to the same wire colors, bundle your wires up into looms, fasten wires up neatly out of the way, etc.

Also, this isn't the final work on how to do a conversion. Every car is different and you should look up information for your particular model. A good thing to do is find a forum on the internet that deals with your particular car. There you can find lots of specific information on your kind of model and maybe even stuff you never even thought of. A little homework can save a lot of fustration.

Good luck!

Re: 6 volt to 12 volt conversion
 

Electrical Conversion

From: Hot Rod Magazine Forum, October 2007, pages 162-164

ELECTRICAL CONVERSIONS

What do I have to do to change over to an electronic ignition on a '49 Ford
original six-volt system, what do I have to change to make it a 12-volt system?
Les Morrill, Humble, TX

To go from 6 to 12 volts, you don't need to change your wires - 6-volt wiring is
twice the thickness required for an equivalent 12-volt circuit. But you do need
a 12-volt battery with the same or greater cold-crank amp rating as the 6-volt
battery it replaces. The 12-volt battery will most likely be standard polarity
(negative ground), but your old Ford is reverse polarity (positive ground).
Therefore you will have to reverse the polarity on selected polarity-sensitive
circuits and electrical devices.

You must address the charging system. You can install a 12-volt generator, but
an alternator is much more efficient. The 6- volt starter and solenoid work: The starter will crank twice as fast, which means the engine should start more
easily, at the possible cost of slightly reduced starter life. One way to extend starter life is to actually promote some voltage drop in the crank circuit by installing a smaller and longer starter cable than standard.

In theory, you can keep the existing points distributor and just install a 12-
volt coil-but if you're going to all this trouble to install a modern electrical system, why not install a modern electronic ignition while you're at it? MSD has bolt-in flathead Ford billet electronic distributors that work with its MSD-6 control box. MSD distributor PN 8573 fits '49-53 flatheads originally equipped with a vertical-mount distributor.

You can retain most 6- volt switches, including the headlight switch, heater
switch, and ignition switch. However, you must replace all 6-volt bulbs -
including the headlights, taillights, brake lights, turn-signal lights, park
lights, and instrument panel and interior bulbs - with 12.volt equivalents. Also replace the 6-volt turn- signal flasher with a 12.volt unit. Finally, you'll have to deal with the 6-volt fuel gauges, electric oil and coolant temperature gauges, electric clocks, and motors like the heater/blower motor, A/C compressor clutch or solenoid, electric fuel pump, and/or windshield-wiper motor [stock Fords typically used vacuum- powered windshield wipers]. However, if it's a custom street rod, you could upgrade everything to modern 12-volt equivalents. If it's an original factory car, the best solution is to use an electronic voltage regulator.

Ron Francis is one source for a universal aftermarket version. It markets two
units: PN VR-l is designed to power low-current devices like instruments and
radios with less than 6 watts/channel output. [Positive-ground radios usually
don't respond well and should be converted to 12-volt operation by Antique Auto Radio or replaced entirely by a modern 12-volt radio.] The higher-current rated Francis unit (PNVR-4) can handle some electric wiper motors and early air-conditioner solenoids; it has a 15-amp rated output capacity. Fifth Avenue
Antique Auto Parts is another source for transistorized voltage drop units,
conversion alternators, brackets, and instructions, and also sells for $10 The
Official 12- Volt Conversion Guide. The guide covers alternators and generators, mounting brackets, pulleys, overdrives, ignition coils, and 6- to 12-volt bulb crossover numbers.

Yet another solution to your dash instruments is to install a factory- style
instrument cluster voltage regulator. Believe it or not, most '60s-vintage
Fords, even though they had 12-volt electrical systems, still retained 6-volt
electrical gauges-so there's a standard replacement regulator for those cars
that could also be used for your application. A common stock application would
be for a '68 Mustang (AutoZone PN IVR601 or equivalent).

The ammeter doesn't care if it sees 6 or 12 volts. However, if you're using a
high-amp alternator that puts out a lot more juice than the original generator, consider converting to a voltmeter the old amp gauge won't read high enough to accurately report the alternator's output, and it's really not a great idea to run all that high-amp current through the dash anyway.

If you're handy with electronics and need to reduce voltage to a high-current
motor (over 15 amps' draw), it's possible to build your own custom voltage
regulator out of transistors, resistors, and a potentiometer. The current-
carrying capacity would equal the rated output of the power transistor inside
the unit. Newark Electronics is one source for high-end electronic components.
Otherwise, there's always the old wire-wound ceramic resistor routine. But it's not a cure-all-only a crutch! Typical automotive-type heavy-duty resistors may have up to a ±40 percent variance from their nominal rating. This means a resistor could take that 12-volt input and output it to any-thing from 2.4 to 8.4 volts. The input voltage can also vary widely depending on the battery's state of charge, changing electrical demand in the vehicle, and ambient temperature changes. Precision close-tolerance resistors are available, but if the input voltage varies significantly, they may not be able to handle the fluctuation in output without failure. And in any event high-power resistors radiate lots of heat. Because of these drawbacks, resistors should only be used as an absolute last resort, and only on devices like motors that are robust enough to handle current fluctuations. They should not be used for delicate instruments or electronic equipment.

Re: 6 volt to 12 volt conversion
 

While you're at it, I would also suggest replacing the Bendix spring. It's probably decades old and subjecting it to extra strain may lead to failure. Just make sure you get a quality item, and not some cheap import.

Re: 6 volt to 12 volt conversion
 

I'm having a frustrating time getting my F1 started. It ran fine last fall but with the summer season going fast the truck will not start and run as it should. This truck has a 8BA flathead with 6 volt negative ground. I just bought a new 6 volt battery with 610 CCA and it simply doesn't have the power to turn over the engine fast enough for it to fire. It will start with a 12 volt battery. I have heavy 00 cables with good connections. I looked for a 6 volt battery with a higher CCA rating but they are expensive and my old "Commercial" (675 CCA) one turned the engine over only slightly faster.
I read through a lot of articles on converting to 12 volts and came up with a plan that is simple and cheap. Install a 12 volt battery. Cut the yellow wire that connects to the battery side of the starter solenoid and powers everything except the starter and splice in one or more 12 volt to 6 volt voltage reducers. Amazon sells them. The biggest I found was rated for 30 amps and costs less than $50 CAD and should be able to handle everything except the starter so there would be nothing else to buy or change. I'm happy with everything except the starter and am trying to keep things as original as possible. I can run an extra wire from the battery side of the starter solenoid to connect the 12 volt radio, cig socket, phone charger, dashcam and backup camera.
Before I return my new 6 volt battery and buy a Group 124R 12 volt battery and order a voltage reducer from Amazon, I thought I would ask the experts about the feasibility of my plan. Is there a flaw in my thinking? Am I missing something?

Re: 6 volt to 12 volt conversion
 

I think this is the start of a new course of action? If so, it would be a lot better to start a new thread, as it is less confusing.

Other than that, all I can add is to ask if you're sure the starter is in good shape? There's a lot that can go bad (bushings, brushes, armature, etc.). I had one that showed the same symptoms (would start fine on 12 volts, but not on 6). I replaced the starter with a known good unit, and I was off to the (6 volt) races.

Re: 6 volt to 12 volt conversion
 

You mention its 6v negative ground, is that a typo or a fact? Should be positive ground on the original system

Re: 6 volt to 12 volt conversion
 

I switched it last year to negative ground after frying some stuff.

Re: 6 volt to 12 volt conversion
 

Now that I've got everything straight in my mind (I hope), I think I see what you are actually asking.

You posted : "Cut the yellow wire that connects to the battery side of the starter solenoid and powers everything except the starter and splice in one or more 12 volt to 6 volt voltage reducers. Amazon sells them. The biggest I found was rated for 30 amps and costs less than $50 CAD and should be able to handle everything except the starter so there would be nothing else to buy or change."

If that's really the question, the answer is an emphatic "NO"! I really think it's time for you to try to find someone who really understands automotive electronics and get some assistance. What you are proposing to do is the ultimate "Band-Aid" and will inevitably lead to more problems.

Start by telling us what you know about the starter; new? used? unknown?

Re: 6 volt to 12 volt conversion
 

This is a common problem. Checking the starter is a good step. Another first step you can do for diagnostics is a voltage drop test to see if or where you are losing voltage to your starter. You may find a cable or ground which has gone bad. Flathead Fever has an excellent explanation on how to do this, https://fordbarn.com/forum/showpost....7&postcount=25

If nothing else, the expensive 6v Optimas are well worth the money. They last forever.

Re: 6 volt to 12 volt conversion
 

The starter is used and came with the engine. It is working as it should but not turning the engine over fast enough. It spins the motor way faster on 12 volts. What specific problems do you see with my proposed setup? The truck would basically run on 6 volts, have the benefits of 12 volt easy starting and being able to use modern 12 volt conveniences.

Re: 6 volt to 12 volt conversion
 

I suspect it may be as simple as a grounding problem. Check all the grounds and make sure they are clean and tight. Also check all the cables and examine them for any corrosion. Make sure the starter has a good ground to the bell housing(no paint or rust).

Re: 6 volt to 12 volt conversion
 

All of this has been checked but back to the original question asked in this thread: What is the best way to convert a 6 volt system to a 12 volt system? Obvious the car companies saw advantages to switching in 1956. So far I have not received an answer as to why my proposed method wouldn't work. I've attached pictures of the converter and my truck. These converters have only been available in recent years and that may be the reason none of the articles on 6 volt to 12 volt conversions don't consider my method which is basically to keep everything 6 volt except the starter and any add-on 12 volt accessories. Auto Parts stores don't seem to carry them but Amazon and Aliexpress do. My F1 is my fourth restoration I've done in my 20 retirement years. On these restorations I have done everything myself including body work, paint, mechanics, respoking wooden wheels and upholstery. I like my antiques to look like they just came from the factory but am not a purist and like to put on extras for convenience and safety. Besides working on my cars I have built my own 3D printer and CNC router and laser from scratch using cheap Chinese electronics. I've also enjoyed woodworking and recent projects have included a pulpit and communion table for my church. At present my health is not so good because I'm waiting for the surgeons to do a valve job on my heart. After that I hope I'll be good to go but I know my age is catching up to me.

Re: 6 volt to 12 volt conversion
 

https://www.fordbarn.com/forum/attac...8&d=1753722432

https://www.fordbarn.com/forum/attac...9&d=1753722432

Re: 6 volt to 12 volt conversion
 

Yellow and green fire hydrants? What is the world coming to! Nice truck.

Re: 6 volt to 12 volt conversion
 

Thanks. I thought I had a great idea in converting to 12 volts but I guess everyone was too polite to point out the obvious flaw in my thinking. The problem is simply that it doesn't account for the fact that a 6 volt generator doesn't charge a 12 volt battery adequately. So its back to getting a better 6 volt battery. I had a size 2 "commercial" 6 volt battery with 675 CCA and 940 CA which worked reasonably well but due to my own carelessness and total surprise it went KABOOM!!!. I was unsuccessful in finding a size 2 battery with similar specs. This morning I picked up a size 4XHD 6 volt Interstate battery with a CAA of 1000 and a CA of 1250 for $168 CAD at a local farm supply store. It's 3 inches longer so I have to modify the battery tray and hold down which is easy to do. It should crank that motor over pretty fast and I doubt that anyone will notice it's not stock size. Problem solved I hope. So my advice is to buy a bigger battery and stick with 6 volts.