Converting from 6v to 12v

[Dodge_48]

I bought a ‘49 B-1-D about a year ago. The previous owner “converted” it to 12v. Well, tried to. He burned out the horn, damaged the wiper motor and fried the heater motor. I was able to clean up the commutator on the wiper motor and rewound the horn coil myself. You can buy a 12v motor that will fit in the model 61 heater from Amazon. Search for “35482 blower motor”.  I found a 25 amp 12v-6v “buck” converter for $75 on eBay and wired it to power the horn, wipers, and fuel gauge. Works great. But, since I had some stuff on 22v and some on 6v, I had to do a bit of wiring.
I would advise anyone considering a 12 v conversion to take the easy and cheap route. Instead of buying a $800-$1000 kit and change over to 12v, just buy a 50amp converter and a single-wire alternator. Replace the regulator with the converter (have someone with electrical experience do this) and everything on the car stays 6v. I found the source for the converters. It’s AliExpress, the Chinese eBay that is operated by Alibaba. China is selling stuff on a fire sale lately. I found a 50amp converter from the same company for under $30 US, and bought 2 for spares. They are robust and well-made by a large Chinese electrical manufacturer - Szwengao. I wouldn’t normally recommend purchasing something from China, but no one in the US makes these. If you’re not averse to a little risk, download the AliExpress app, get a separate debit card to buy them with (just to be safe). 50amps is overkill, but they should last a long time. Hopefully. 

[Sam Buchanan]

Or install a 6v alternator, keep the 6v battery and drive happily ever after.  😁

[Ivan_B]

I like 6 volt 😅

 

Thank you for the tips, though. There is no reason to be biased against Chinese parts, in particular. They can make cheap things, they can also make good things like iPhones, etc., it is what ever you want to pay for.

[Dodge_48]

 It can Bevtough getting a car started on 6v in the winter, and generators are getting tough to come by, though I did find a shop that still rebuilds them. Problem is, they don’t look like original equipment at all. And, you’re right about Chinese parts. They do make some quality stuff. These converters appear to be well made and certainly worth the money.

[Los_Control]

12 minutes ago, Dodge_48 said:

just buy a 50amp converter and a single-wire alternator. Replace the regulator with the converter (have someone with electrical experience do this) and everything on the car stays 6v.

What charging system are you using? ..... In the past and even today it is cheaper and easier to just convert from 6V > 12V.

I'm using a 12V 65 amp chebby alternator ... because I have reading comprehension issues .... cant read worth a crap! I wanted a single wire internally regulated but purchased a externally regulated .... so that added a extra item to wire in ... (regulator)

 

All the light bulbs need to be changed, you will need a $12 voltage reducer for your fuel gauge, probably better off to buy a 12V heater blower motor. I would imagine the horn would work on 12 for awhile, unless it was worn out in the first place or they just layed on it and over heated it.

 

You must live good to have electric wipers in a B1D .... My B1B has vacuum ..... again a $12 converter would fix that ......

 

I just do not understand the $75 buck converter or the 

31 minutes ago, Dodge_48 said:

buying a $800-$1000 kit and change over to 12v, just buy a 50amp converter and a single-wire alternator. Replace the regulator with the converter

Just kind of sounds like you got lost in the weeds on your conversion that you inherited when buying the truck.

 

I figure I will have $300-$350 into a complete new 12V wiring system.

I needed a new wiring harness. $75 for a basic 12 circuit from Amazon.                 $75

Alternator/regulator about $75 from rockauto.                                                           $75

I bought a 3 pack of the 12V > 6V converters from Amazon for $20                        $20

All new bulbs including 2 new truck tail lights ... $50                                                 $50

The different ends, extra wire, switches, flashers .... guessing $100                        $100

 

So I already have $320 into it and just collecting parts ..... Someday I'm going to wire the truck! But I have everything for it .... And it is cheaper to go 12V then stay 6V ... IMHO

 

[Sam Buchanan]

16 minutes ago, Los_Control said:

And it is cheaper to go 12V then stay 6V ... IMHO

 

 

I'm not following the cheaper to go 12v unless you are referring to the incredibly complicated system the original poster is describing.

 

Less than $150 for a new 6v alternator and nothing on the car has to be changed. I would, however, upgrade to the proper 6v battery and starter cables if they are not present, that will solve the cold weather starting problems.

 

[Sniper]

Why is it whenever anyone asks how to convert to 12v the anti-12v crowd jumps in with why not to?

 

If they asked the pros and cons, yeah that would be appropriate.

 

If you want any sort of electrical accessory you are either stuck with archaic, poor performing 6v stuff, Am radio (or beaucoup $ conversion), poor headlight choice (6v incandescent or crappy LEDs). 

 

It is what it is.

 

 

[Los_Control]

50 minutes ago, Sam Buchanan said:

I'm not following the cheaper to go 12v unless you are referring to the incredibly complicated system the original poster is describing.

I'm guessing it was around 1975 and living with my sister/BIL .... I was a bad kid and got kicked out of school, so went to live with them to continue school in a new district 

I was helping the brother inlaw convert some old hoopty over to 12 volt. I asked why?

Car was not charging, A new generator was expensive the battery was weak and needed replaced .... It was a lot of $$ back then to maintain a 6V system.

He could get a used 12V battery from the wrecking yard for $5, A used alternator, light bulbs .... everything needed for less then $50 at the wrecking yard.

It literally was cheaper to convert the car rather then keep it 6V.

 

Same thing today, it is cheaper .... Especially if I went to a wrecking yard and bought all common parts that are needed .... My price list is all new shipped to my door.

 

I have far more advantages over a 6V system, it is cheaper to maintain, It just rocks my world to be 12V.

If I wanted a 100 point show car trailer queen, 6V would be mandatory ..... A 49 Dodge truck that hauls dogs and firewood, 12V is perfect.

 

[Sam Buchanan]

I am definitely not anti-12v. All my old 60’s VWs were converted to 12 volts for some of the same reasons stated here. But if I had a vintage Beetle now it would probably remain 6v just for originality. The ‘69 Beetle I drive now was produced with 12v and it’ll stay that way.

 

The only reason I mention 6v is because some have had bad experiences with faulty 6v cars and don’t know how well a good 6v system will work. We have new members arriving and to some of them a 6v system is totally unknown to them. My intention is to help those who might find updated 6v service histories useful so an informed decision can be made.

 

It is good to have choices.

Edited March 28 by Sam Buchanan

[Ivan_B]

56 minutes ago, Sam Buchanan said:

The only reason I mention 6v is because some have had bad experiences with faulty 6v cars and don’t know how well a good 6v system will work.

That is very true, and the same goes for things like electronic ignition, modern carburetor/FI, disc brakes, oil bath filter, and just about anything else people do not necessarily know how to work with

[Sniper]

My primary issue with a 6v car is head lights.  I drive my stuff, regularly.  In rain, snow, shine or whatever.  With regards to incandescent head lights, well I may as well hang my Zippo out the window for all the good those lights do.

 

I believe Keith did a write up on 6v LED headlights awhile back, not too impressive.  I know a guy that is really into automotive lighting and he's pretty much death on retrofit LED headlight bulbs and has the data to back it up.  I am running a set of GE Nighthawk LED headlight assemblies in my 51.  They light up like modern lights, as they should since they are designed as a unit and not as a bulb retrofit. 

 

Anyway, to each their own.

[Tired iron]

I'll steering clear of the 6 vs. 12 debate -- to each his/her own opinion -- but if you are going to convert, I found it to be much less complicated than some folks make it.  I put in a one-wire 12 v alternator, swapped all bulbs to 12, new 12 V coil, and swapped polarity on the coil and ampmeter cause I wanted neg ground.  I don't know if I would have converted if my car had been in good running shape, but my car was a junkyard find and the gen was shot and most of the bulbs were toast!

 

Now my horn is loud but works fine, my starter loves the extra juice, fuel gauge is fine, and I've got all kinds of choices for a good sound system.  No converters needed.  I haven't swapped the blower motor yet, but will per sniper's and others recommendations.

[soth122003]

Reading the post, I think the three big reasons that people upgrade to 12v are as follows. 

1. Diving factors.

2. Safety reasons,

3. Ease of maintenance.

Do you drive all the time or just occasionally? Driving it all the time? then the 12v conversion makes sense. You want the lights brighter for safety. Accessories? 12v gives you more options for music, phone chargers, air pumps stc. Maintenance costs? 12v may be cheaper in the long run. Generator requires brushes and oil, The VR may or may not be reliable. Some last years and some last months or days. Batteries? 12v may be cheaper or at least more readily available. The 6v battery may be sitting on the shelf for months or years, depending on where it is purchased, when you need one.

 

That said, if you drive you car 2-3 times a week for short trips or the Sunday drive or the fair weather driver? The 6v originality is fine. Myself? I don't drive in the rain or at night if I can help it. Same for high traffic days (crazy drivers out there). Just watch a Letto's Law episode yesterday. 18 year old girl driving a Corvette at 155mph killed a motorcyclist. At NIGHT!

5 seconds before impact she was doing 155mph. When she hit the guy she had slowed to 87mph. NUTS. 

This is also due to the inexperience of younger drivers. (think Newtons law) Not to mention the distractions of the cell phone.

 

Anywho. Most of the people I see doing the upgrade to 12v are the one who buy the DIY restoration car with the intention to use more often for a daily driver. Hence the upgrade to 12v, disk brakes seat belts and such. 

 

Myself? I like the 6v system. I like the Sunday drive or the short trips around town. Radio? I have a bluetooth speaker and an old phone for music. I smoke so I love the wing windows on my car. Only time I want AC is at long stop lights otherwise the cowl vent and the windows are fine. The key take away I have is these cars are 70, 80 and 90 years old. They can't compete with newer cars unless you change out most everything under the body. 

 

Now for all this blathering of 6v vs 12v I am still firm believer in "It is your car so do with  it what you will". I may not agree with you choice, but it is your choice and not mine. So I will offer advice and opinions and like all advice and opinions they are butts, some people wipe good and some people wipe poorly.

 

Joe Lee

[Dodge_48]

I started quite the discussion on 6v vs 12v. On one hand, if it’s 6v and it works for you, why spend the money? If you want to go to 12v, you’d typically replace the bulbs and coil of course, but the biggest issue is that you have to figure out how to deal with 6v motors on the wipers and heater, and likely the horn. I have been told by many that the 6v starter will be fine. As I pointed out, the previous owner of my truck fried some stuff when he did it. If you want to go with a 12v system, you’ll need to find 12v replacement motors for the wiper and heater blower motor. One option if they aren’t available is to buy a 12v to 6v converter to drive the 6v motors. If you are buying a converter, they are dirt cheap right now, and rather than have mixed voltages in the vehicle, one option is to install a 12v alternator and battery, and buy a converter with enough capacity to drive everything on the vehicle with 6v. If you want to add a 12v stereo, you can drive it off the 12v side of the converter. It’s just an option.

[Sniper]

One other thing to seriously think about, your stock wiring is probably toast or close to it if original.  While you can get the correct 6v rated harnesses new in many cases they aren't cheap.  If you put in a generic "hot rod" harness like the PO of my 51 did (real hack job too) it's not rated to handle the current a 6v system runs thru it.  I ripped it out, put in a new hot rod harness and converted to 12, didn't count the cost of the harness in the conversion as it was required regardless.

[Los_Control]

1 hour ago, Dodge_48 said:

I started quite the discussion on 6v vs 12v.

Everybody has a opinion. ..... We are considered caretakers to these old cars. It is up to us on how good of a job we do.

Some people are really good at keeping them exactly original and I love them for it.

 

Some of us have connected a winch and drug them out of the grave. ..... This truck had a wrong used generator installed that does not work.

The original wiring was non existent ..... This truck is a beater with a heater, A new 6V wiring harness requires heavy wire for more amps $$$

I would feel like a idiot to spend the money to put this back to original 6V .... When a 12V system is cheaper and superior.

 

Same time if I owned a beautiful survivor, I would do everything I could to keep it original 6V ...... My truck is not that vehicle.

 

Since I went with cheaper 12V, I'm going to get my CB radio, I want a decent stereo, I want to run the slant 6 electronic ignition. I want to try led lights .... I have a whole new world opened up to me.

 

12V is for me, it is not for everyone.

 

 

 

[Dodge_48]

Your truck looks really straight from the pic you posted. Very nice. I actually have two. I’ve had my 48 for well over 40 years. I can’t tell you how many miles is actually on it, and it still purrs like a kitten. I really enjoy driving that truck. It was my everyday driver for many years. I picked up the 49 about a year ago for parts. It’s pretty rough, but it’s got some good parts. I’m planning to put together one really straight truck out of the two. Both have their original wire harnesses, but being fabric wrapped rubber (or whatever), the insulation will fall apart if you mess with it. I’m on the fence about whether to buy a factory-style wire harness made with the old-style wire, or just run all new modern wire and build-up a new harness myself. I think the last time I looked, a new replacement harness is about $800 these days. On one hand, I could probably use modern wire and do it for a lot less. On the other hand, I’m trying to keep it as close to original as is reasonable. I dunno. Gunna need to decide before long.

[keithb7]

12V if you prefer. That’s fine. I like 6V for old school cool factor.  I like it when young drivers want to check out my old car.  I point out the positive ground 6V system with a generator. Vacuum wipers. Suicide doors. Tube radio. Split hood. Flathead engine. Bias tires and more.  They are often stunned and awed. I like being a custodian and teacher for these old systems.  That’s just me. 
 

 

Edited March 30 by keithb7

[Racerstev]

I was rolling around a series-parallel switch. 12 volt for the starter and 6 the rest of the time. This is a diesel truck trick. But were to put two 6 volt batteries?? 
 

I just started the 12 volt conversion on my 39. For me the problem is lack of confidence in the cranking speed. Yes it starts but I just don’t trust it. If I don’t trust it it won’t get driven as much. 

Steve

[Sam Buchanan]

8 hours ago, Racerstev said:

I was rolling around a series-parallel switch. 12 volt for the starter and 6 the rest of the time. This is a diesel truck trick. But were to put two 6 volt batteries?? 
 

I just started the 12 volt conversion on my 39. For me the problem is lack of confidence in the cranking speed. Yes it starts but I just don’t trust it. If I don’t trust it it won’t get driven as much. 

Steve

 

Rest assured I'm not leading the 6v marching band. But I think something we need to consider is these old cars were daily drivers back in their day and they started reliably. People weren't converting them to 12v just so they could get them started every morning.

 

I have to wonder how many times a 12v conversion is performed just as a band-aid applied over systemic problems such as poor wiring, a sluggish starter or a battery that isn't being kept fully charged by an anemic generator. Perhaps many reliability concerns could be addressed by making sure the existing 6v system is in optimum condition by addressing basic maintenance issues. These old cars worked very well in their day, there is no reason why they can't be as reliable today if the electrical system is in good condition.

 

Having said that a set of good battery and starter cables along with an alternator will go along way toward keeping a 6v car happy. 

[Young Ed]

I'm sure it's sometimes a bandaid. My 48 had toast wiring. I pulled the entire harness and rebuilt it using modern wiring. As an upgrade and to consolidate sizes all the 16 went to 14. I've now put about 30k miles on it with the 6v system. 

[Sniper]

Ii think the biggest issue with 6v, especially when they were new and in daily driver status, is that there is little reserve.  Remember having to pull the battery and keep it inside during cold weather?  Combine a cold battery with thick oil due to low temperatures and cold weather starts were interesting.  Not too sure many of us drive them in those conditions any more.

[Kilgore47]

 

Had the same slow starting problem with the 47 P15.  Re wired the car with a new 6 volt harness and no difference.  Added 00 battery cables and no difference.  Finally I got a good AGM 6 volt battery with 1000 cold cranking amps.  Problem solved.  The car can sit for months and it still starts.  No priming pump.  On the third try gas gets back to the carb and it starts up and runs good.  I also switched over to an alternator.

[Sam Buchanan]

7 hours ago, Kilgore47 said:

 

Had the same slow starting problem with the 47 P15.  Re wired the car with a new 6 volt harness and no difference.  Added 00 battery cables and no difference.  Finally I got a good AGM 6 volt battery with 1000 cold cranking amps.  Problem solved.  The car can sit for months and it still starts.  No priming pump.  On the third try gas gets back to the carb and it starts up and runs good.  I also switched over to an alternator.

 

Excellent! I suspect the alternator is a fine upgrade to keep the mongo battery hot....doubt the old genny could feed that monster a proper diet!

 

Healthy starter......hot battery.....good wiring.......reliable starts. 

Edited March 31 by Sam Buchanan

[D35 Torpedo]

I fired my 6v car up yesterday after sitting for months. I had to crank it for a while before fuel got to the carb. It was a little slower than normal, but she didnt quit, and it started up just fine. My system is all oversized and fairly new. I put 6k miles on it last year trouble free. I ran 10g for the headlights with a 6g common ground cable running to the junction block up front. That serves as a ground for everything up front. 40/50 watt headlights are plenty bright. I did it all pretty cheap, mainly because I had a large stock of wire that I aquired years ago and a good gen/VR. If i was starting with nothing, id consider 12v, but im a purist and like to keep things as they were. Conversions are always a spicy topic, end of the day, the only one you need to impress is yourself.