The Stovebolt Site Forums The Shop Area The Electrical Bay Why upgrade to 12 volt?

I found the how to do it in the tech tips, and I've found a lot of threads of people chasing down all the related upgrades they find it requires, but I'm not really seeing anything on the why?

The obvious is that we live in a 12v automotive world, so making the change will result in an easier time finding batteries and such, but on a day to day use is there an actual noticeable difference between driving a 6 volt and 12 volt truck?

The advantages to availability of some parts seems like it might be offset by not having the ability to use stock equipment, making every future replacement require checking compatibility from a later 12v vehicle parts.


Would really like to hear from those who have done it, or have actively decided against doing it. I am particularly interested in hearing from those those who are maintaining a mostly stock truck appearance.


If I were to do it, it makes sense to me to get in and do it while I'm bringing the truck back to life, not get it running then tear it apart again.

Here , 6v items are not so easy to find .
Daily use , the truck starts real fast , headlights are brighter , I've got no radio , so that's about all for me .
Still happy with the change .

I went back to 6v after being 12v for several years.

After:
- cleaning all battery cable/strap ends and connection points, and
- applying ant-oxidant copper-impregnated grease, and
- making sure all battery cables and straps are no smaller than 2 gauge (00 gauge on one truck)

I have had no problems for over 14 years.
My 14 year old 6v Optima battery is still going strong.

One problem I had to remedy was/is dim lights from poor grounds where fixture screws/bolts ground where the attach to the body/etc.
I am satisfied with my 6v radio.

If I wanted to add more-modern accessories, I'd change to 12v.

I've gone 12-volt mostly for better lights driving to work in the winter and having a modern AM/FM radio. The very quick starting with the original starter was a bonus.

Here's a picture of the $70 12-volt Sony radio in the glove box.
Note: The original radio has aftermarket knob bezels.

Old and New Radios Installed
.

AaronW,
The primary issue with 6 volts is that for a given job to do, for example headlights, it requires twice the current. By design the 6 volts lights are every bit as bright. But over time, as corrosion creeps into connections and the switch, resistance builds up and the lights dim. Or the starter doesn't spin like it used to.

The other issue is accessories, like a modern am/fm radio or aftermarket wipers, all which may require 12 volts.

I like to try to stay original and am quite satisfied with my trucks that are 6 volts. When I restored my '50 COE I was surprised how bright the 6 volt headlights were (and still are 6 years later). I do not, however, use any of my trucks as a daily driver. If you are having dim headlights, difficulty with warm starts (starter is not spinning) I would try first to go through and clean connections, grounds, etc. If you are not having problems and don't need a modern stereo system or air conditioning leave your system alone. Six volt items like bulbs, voltage regulator, coils, etc are not hard to find through the old truck vendors linked on this site.

Kent

Agreed, Kent

Also, there are now 6v LED bulbs that are as bright or brighter than original 6v bulbs.

I have not yet tried/installed the hi-intensity 6v motorcycle headlight bulbs that fit the 47-55st housings.

I'm running 6 volts and it is very OK. I do have a 60 amp, 6 volt alternator. I've made the following mods, relays on the headlights (take power directly from the battery to lights) they work as well as some 12v modern lights I've had. Relay on the heater, blower fan runs much faster. The biggie is I have a 6 to 12 volt, 10 amp 30is $ Amazon step up transformer this one. It powers my $29 remote controlled AM FM, blue tooth radio. I've also installed 6V LED tail/brake lights for safety.

With the above upgrades, 6V works great for me.

RR

One the reasons why people upgraded from a 6 volt system to 12 volts system.
Is because, Unknowing owners mistakenly replaced their original worn battery cables with incorrect gauge cables.
Two ground cables are also required: One from the battery to the frame and one from a starter mounting bolt to the frame.
Most of today’s auto parts stores only stock the smaller diameter 12 volt designed cable.

Six volt starters require twice the electrical flow to operate properly. Don’t blame your six volt system for slow unacceptable starter motor speed! Many restorers go to the expense of changing their 6 volt system to 12 volts. They feel their original system was inferior and believe what they did was necessary. The problem could have been corrected with just adding the three proper cables.

Remember: Millions of cars and trucks were made with 6 volt electrical systems each year.
If they had not operated correctly they would have been built with 12 volt systems!
Speed Up 6 Volt Starting

Also electrons flow on the surface of the conductive material not through the center.
The more surface there is the better, multi stranded cable is ideal, I like large diameter welding cable.

Another reason why they changed from a 6 volt system to a 12 volts system.
It was getting harder to start the high compression OHV engines on 6 volts,
plus run all the power accessories such as power seats and air conditioning that were coming in at that time.

Everything you said is correct. Your analysis is spot on. You asked Why and you answered your own question. If you have read the Tech Tip section on here re 12V conversion you will see that some "stock equipment" is used with voltage reducers and some equipment is changed to 12V. (chasing it down is a matter of ordering online or FLAPS, I believe the Part No.'s are given in the tip). You will know in the future what to buy because you did the conversion and there is not allot to remember. Seems simple because it is. If you decide to do it or not do it, you will join hundreds of people, either way, who are satisfied. In my opinion, if you are not a purist, converting to 12V makes sense for parts availability especially out on the road. Many folks have other reasons, like swapping in a V8.
It does not change the appearance much. Depends on your definition of appearance. We live in a 12V world with alternators cranking suitable amps. All the swap parts are cheap.

I hesitate to say I converted to 12v because I never ran the truck with 6v. I did a frame up restoration and saw no reason not to use 12v. Since the battery is under the passenger floor there isn't really any way to tell it isn't 6v. All the necessary parts were readily available. I retained the 6v starter and the truck fires instantly. The lights are bright. I had enough slow cranking and hard starting with 6v vehicles in my youth. Granted, with new components and good electrical connections 6v will function okay. For me I can see advantages and no disadvantage to using 12v.

I would have to agree with you Chuck, your thought process seems spot on. Besides the big 3 all decided that too over 60 years ago. Unless you are a purist and want it correct. I just did a body off and retained the 6 volt, used all the correct large battery and ground wires, the headlights are grounded well but still today's 12v lighting technology is indeed much better, no arguments for sure. In hind sight if you plan on driving a lot in the night, 12 volt switch is the only way to fly. Plus we haven't even talked about high power stereos and power windows/door locks and the alike that people put in.

Steve

Since we are going in circles, I'll keep the circle unbroken:

"Would really like to hear from those who have done it, or have actively decided against doing it. I am particularly interested in hearing from those those who are maintaining a mostly stock truck appearance."

I have successfully gone from 6v to 12v and stayed with it - no problems (on a '54 pickup). It is a happy truck

I have successfully gone from 6v to 12v and back to 6v (my '54 Suburban). It is a very happy truck.

I will stay with 6v on my '54 pickup that will "all original type/looking equipment" (it is ready for final sheet-metal painting).
This truck might have a 6v original radio, or 12v look-alike radio (using a $50 6v to 12v converter for radios).
It will be a proud and happy truck.

If your grounds (everywhere) are good, and your generator/regulator are good and well-adjusted, 6v your lights will dim very little, if at all, at night.
If you change to 6v LED bulbs (available in 6v for all bulbs, except headlamps), they will be as bright as 12v bulbs.

If you need/want 12v devices, go 12 volt before buying 6v electricals.
Although, 6v to 12v voltage converters are available and are reliable (and, are relatively low-cost) for low-draw devices.
If you want a boomer sound system, or an AC system, change to 12v.

Considerations/concerns/complexities that are commonly posted/argued-over regarding 12v:
What 12 alternator/generator/voltage-regulator combination (and, wiring for that combination and components)?
What 12 distributor/coil/ignition set-up (and, wiring for that combination and components)?
Wiring/protecting your 6v fuel gauge and 6v ammeter gauge?

That is about the best encapsulation of the 6/12 Volt conundrum I have seen on Stovebolt. Coming to full circle,
I offer a Jerry style tribute.

joker would be proud of you, bartamos.

AaronW,

What ever you decide remember, it's not irreversible! Go for it whatever it is!

This was my solution.

At one time in my 1954 panel I had both a 12 volt battery and a 6 volt battery.
The 6 volt battery was in the original floor location and the 12 volt battery was mounted on the passenger side fender skirt.
Along with the original 6 volt generator, I mounted a 12 volt alternator with a built in
regulator on the opposite side of the engine, both turned using a single fan belt.
I solid mounted the alternator and used the 6 volt generator belt tension adjustment to tighten-up the fan belt.
The 12 volt battery was used to power a 12 volt high wattage sound system.
The 6 volt battery was used for the truck's original electrical system.
Both batteries shared the same ground.

After playing the sound system for a couple hours, with engine off, the 12 volt battery would drain down dead.
I would kid everyone that we were stranded.
Then I would hop in the truck and start it up with the 6 volt battery.

Adding a 12 volt alternator and battery is a lot easier/cheaper and less invasive than a 6 volt to 12 volt conversion.
Used junkyard 12 volt alternators are a dime a dozen, compare that with what it would cost to convert to 12 volts.
The 12 volt alternator and battery add on system can be easily removed to bring the truck back to its original factory state.

I think I used the the 12 volt battery to jump the 6 volt battery a couple times.

Thank you, although it breaks down pretty evenly both ways that also shows there is no right or wrong answer.

I will wait until I get really dig into the truck and see where I stand at that time. If I find I have significant work in the electrical area it might make sense to look more seriously at going to 12v, if things look pretty good as is then no rush.

The truck will be a project, used locally as an occasional hauler to the dump or from the hardware store for home DIY projects. We have a 50s themed diner that attracts old cars on the weekends and a couple times a year there are old car events in town that might be fun to participate instead of just drooling over others vehicles. Very casual, no plans for any kind of hard core contests that check the purity of every nut and bolt used in a restoration.

Yet, No one has addressed the simplicity of the Alternator (diodes, Regulator) inside. Compared to the Dynamo using brushes and a external voltage regulator.

I'm still running 6v electrics in my 49 3100. To get it running 5 yrs ago the new Napa 6v battery set me back $120 and is still doing it's thing. Shortly after getting it roadable the regulator would take a tap or two to start charging. A simple cleanup of the contacts and adjustment of the relay points corrected that. Once after a good engine washdown the generator stopped charging, a simple swap out of the brushes corrected that. I drive it every weekend and it's not failed to start and run for the past 5 yrs & 21K miles. I wanted a tach and power port and decided to add a circuit just like moparguy linked to and the truck now has a separate circuit that can provide up to 10 amps at 12v. The tach is great to have and the power port has recharged my cellphone & works a Garmin GPS when the need arrises. If it had a modern radio it would power it also. For a Christmas parade I plugged in an inverter and powered a string of blinking lights I had draped around the contours of the truck.
All that said if/when the battery or 216 bites the dust I'll be going to a complete 12v upgrade. And integrate a big ole third brake light where all those tailgaters can see I'm stopping.......

This particular item applies across the board to filters, distributor etc which is another kettle of fish I'm weighing. This truck is the oldest I've dealt with but it seems with all older vehicles you have to balance ease of maintenance with originality.

That is the only reason I went to 12 volt alternator on my daily drivers. I am not smart enough, nor patient enough to troubleshoot a generator/voltage regulator.

The reason I go to 12v on EVERYTHING is I'm cheap and I'm lazy. I don't have to do any special search for whatever part I need and the big box stores have them dirt cheap. Not so for a generator/regulator/battery for 6v application. Everything from fuel pump to cooling fan can be bought from the local FLAPS or cheap online.

I agree with Evan and Carl, it's the simplicity of the whole 12 Volt system and not having to worry about it going forward.
I did some work on a 41 Willys MB a couple of years ago. The family had owned it for 30 years and took it with them for camping & hunting trips. The current owner said they had starting and charging issues with it as long as he could remember. He said his dad parked it on a hill everywhere they went so they could be sure to get it started. I did a 12 volt conversion with a 10SI alternator along with a major tune up, brake work, and some other maintenance work and it has been going strong since.
Fred

I used to park my 6v vehicles on hills (40 years ago), until I learned about incorrectly-sized battery cables AND straps, and until I learned about bad grounds/connections due to rust/corrosion.

My guesses regarding the cause of starting problems "unique/common to 6v":

75% of 6v starting problems - wrong straps/cables
20% of 6v starting problems - bad connections (there are 6-8 cable/strap connection points)
5% of 6v starting problems - bad/weak/old battery - one of my 6v Optima batteries has lasted over 14 years

I have no problems now starting my 6v vehicle, even after winter hibernation.

OF COURSE: if you need 12v devices that draw a lot of current, you would most likely want to completely convert 12v.

I am as lazy as Even, but stupid to boot. One day I would like to build one of these trucks just as designed and maintain it just to be able to say that I did. I had one at one time, but plans got changed mid-build due to someone coming along with a pile of money to build it "his" way.

My '46 6400 is still 6v and will probably stay that way. I converted one of my farm tractors because everyone said that was the way to go, but it would have been easier to just replace the corroded battery cables. Granted the engine cranks faster than it idles, but my other tractor starts just as well on 6v as does the truck. The only downside I see is trailer lights, but most towing is done with my modern van.

Ed,

Regarding: "The only downside I see is trailer lights, . . "

What is the downside regarding trailer lights?
What are the bulb size/code (sizes/codes)?

Tim, the trailer light issue for me would be my trailers being pulled by multiple trucks (12 volt). Also most have 12v electric brakes. That said, I have considered building a light 2 axel trailer with 6v LED's and surge brakes for the 51 and it's 6 volt system.

RonR

RonR,

I understand your concerns with trailer lights.

Superbright LEDs had almost all the side/marker and rear lights for my 54/55 6v (positive ground) COE flatbed.

The only lamps they did not have were various bright, mutli-LED lights/lamps, like back-up lamps (they might have them now).

https://www.superbrightleds.com/search/led-products/6v+led/

Also, there are dependable and inexpensive 6v to 12v power-converters that work quite well and reliably with 12v leds. The LEDs are easy power-draws for any voltage converters.

My concern for my trailer which has all LED lights is the electric brakes on it which requires 12v. I would like to keep it 6v cause it starts right up and I haven't had any issues. Will an up converter from 6v to 12v work for the brakes or should I stick with my plan for 12v all together?

I have a friend with a 6v 1953 GMC that has used a "6v-12v up converter" with great success. Including a 7,000+ mile cross country trip and 40,000 miles since the year 2000.

What was he upconverting? I'm not sure if an upconverter will work for trailer brakes.

I am not sure about the electric brakes - I did not refer to that issue.

What is the amperage need for that device?
(an example?)

Are 6v to 12v converters not available (not possible) for that device/application?

I'm not sure of the amperage but I've pretty much decided to do the 12v conversion. I'm leaning towards the 10si as everyone seems to have very good results with it. My only question would be would a 63 amp work if down the road I win the lottery and add A/C? I would think it would as they worked in Camaros with A/C in the 70s. With not much more electrical in the truck other than lights, I think it would be sufficient.

Wait til you fire a 6v horn with a 12v battery. OMG! so awesome!!

A 61 amp 12v Delcotron Generator (K76, pg 36) is listed as being available for the 1967-1973 Camaro (with or without the A/C option).

Google search

Just what I was thinking, 10si 63 amp alternator.

Another question about the conversion. Is there anything special I need to know about have a floor starter? Seems like I read somewhere that there is something different as far as parts to buy when you have a floor starting vs key starter.

There is no need to change the starter. Your 6 volt starter will live many years on 12 volts. 🛠

Thanks.

I am also seeing in some Packages that are offered like from Vintage Garage and it shows a headlight relay switch. Won't I just put in 12v bulbs for the headlights and that should be good for those? What am I not thinking of that would be the reason for a headlight relay.