12V or not to 12V

B

Big_Guys_baby

Senior Member
Hey Barners,

My 1946 Biz Coupe, currently 6v pos ground is having a hard time keeping the battery charged.

It looks like my generator is coming down the end of its life. Put new brushes, cleaned up the armature, extra grounds, double checked battery charge level, new obligatory voltage regulator... The car will run at fast idle when I pull off the battery but it isn't putting out enough to keep up with charging it. While driving and volt meter hooked up it looks like the max is 6.6volts coming off the generator.

When I replaced the brushes I noticed the end of the armature was grooved pretty bad, but didn't have a growler or access to check for shorts.

Before I sink any more $$$ into the 6 volt system, I am seriously think about jumping up to 12volt. The primary goal for this vehicle is going to be daily driving as much as possible, and I do end up having to drive home at night a lot for my job. Brighter lights, and charging reliability is a huge factor for me. Al

Just wanted to see what the hive mind had to say about that!

Thanks!

Jeff
 
You will never regret changing to 12 volt. I changed my 48 to 12 volt and i love it. Cost was not that much. I used a G.M. single wire and voltage drops on the gauges and clock, changed the bulbs and that was it. Try it you will like it, and if you want to go back to 6 volt its very easy to do so. Just my 2 cents.
 
Did you use one of the generator to alternator mounting brackets like they sell through Mac's? Any problems finding a belt to line it up? I assume you also switched out the starter solenoid to 12v and coil as well?
 
12V is a change you will never regret along with the one wire alternator. Not to mention 12V halogen headlights. I believe you can buy a generator that has been converted to an alternator if you want to keep the OEM look. You can also convert to electronic ignition.
Just think......no more points.
 
I have been searching, does anyone know if there is a good "how to" thread on here about converting to 12v?

If there isn't, I will make a conscious effort to take lots of pics and detail my effort on here, since I see the question come up a lot.
 
To me it is a toss up. I have both and have no issues with either. The `35 is 6 Volt with a modern cut-out on the generator and an Optima battery. Have not had a problem keeping the battery charged. The `51 F1 was already a 12 volt system when I bought it. I had to put a new alternator on it as the old engine was a six cylinder and I replaced it with an 8BA. To me it wasn't worth the expense to change either of them out as they both work well.

BTW when did we get spell check? I just noticed the red underlines.
 
My '35 fordor sedan is 6v positive ground and the charging system has worked great for the 22k miles that I have driven this car. There are no incentives that I can think of for me to convert it to 12v. The generator, the modern cutout/regulator, and the Optima 6v battery all work fine together for a trouble free system. Going to 12v is no guarantee that you will never have the same problem that you have now with the 6v system.
 
Perhaps the regulator is not adjusted properly, I drove a 46 for many years, night and day (only car I drove)never had a good battery, but the lights were bright

Proper restoration eliminates the "need" for most modifications

Your stock 6V system should have no problem running 6v halogen seal beams, I ran them on a stock electric system 46 truck truck that was driven much of the time at night

Because my A has bright lights and cranks fast I get comments that I must have 12V, but it is 6, the last battery lasted 16 years without xtra charging, never charged while sitting for winter etc. ,---i have quartz halogen bulbs in the headlights and drive a lot at night with the stock generator, havn't touched the starter or generator for 40 years ---the chevy truck I have had for 35 years has had the alternator and starter apart at least 3 times each in the same time frame

The same effort to do a 12v conversion properly should fix the 6V system ---your car may just need the voltage regulator adjusted
 
It depends on what you want to do. I converted my 8ba to use a crab ignition with points and kept the generator stock. I also have early style heads. I prefer that look. The generator is adequate for my needs, stereo and electric fan(if needed) during the day and stereo and lights during the night. I use a 12V dry cell battery which is located under the passenger seat.
 

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I had to re-wire my '49 about 5 years ago as they were all still the original from '49 but kept it 6 volt. Re-wiring made a world of a difference in all systems - running, starting, lights etc. Just saying that if all the wires and systems are good the 6 volt should work just fine. Have never had any problem with keeping battery charged. I'm sure the 12 conversion works well for those who have done it, but the 6 volt still works fine for me.
 
Hello Everyone, Jeff I really like your car and admire the story.

I think George49Ford above may have a point worth considering.

If the change is from 6 to 12 but uses all the same (possibly high resistance) wiring.... Hmmm.

If the wiring is anything like in our '36 it is fabric covered twisted copper strands with bullet connectors joining the various wire looms. The 75+ year old fabric covering is breaking down and it could really use a re-wire if it is to be seriously road-worthy. I avoid touching if it if possible, it just seems to make things worse.

Just sayin'

Oh yeah, full disclosure, I vote 6 volts. That's the way it was built and designed. I'm at heart an Antique Car guy. It can be repaired to do the job, I think people are puzzled by the old systems, ie. Brakes, Shocks, and Electrics. With the other guys, the sharp minds here on the Barn, you can be talked down from any ledge.

-VT/JeffH
 
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Big_Guys_baby said:
I have been searching, does anyone know if there is a good "how to" thread on here about converting to 12v?

If there isn't, I will make a conscious effort to take lots of pics and detail my effort on here, since I see the question come up a lot.
Click to expand...

I have been very happy switching to 12 volts. It is easy to do. A good source of information is a booklet called "Official 12-volt Conversion Guide" by Randy Rundle. (PM me is you are interested in his phone no. or internet address)

There is a lot more work in installing a modern wire harness although it opens more possibilities (accessories).
 
Thanks for all the info guys! Every inch of wiring has been replaced in the car, with the sole exception of the horn wiring down the steering column. I enjoy doing electrical work and have been pretty meticulous on it, added lots of extra grounds, etc. Perhaps I should redouble my efforts to find an automotive electrical shop in my area that can look at the generator and bench test it properly. I too like the look of a generator much more than an alternator, but don't want to shell out that much for the powergen alternators! lol
 
I have original wiring in my 49 F1 and run 6 volts. I have a new wiring harness but haven't got around to fitting it. About 30 years ago I put some new brushes in the stock generator. No issues - I drive my pickup like its 1949 and my Toyota like its 2014.
 
Big_Guys_baby, A 6 volt system is all good if everything is GOOD. Yours is not good because the generator voltage output is ONLY 6.6 volts. That will never keep your battery charged up. Voltage regulator setting should be 7.5 to 7.8 volts. Get some one capable (auto electrician) to adjust your voltage regulator and you will be good to go. No need for 12 volt system. Regards, Kevin.
 
I planned to convert to 12V even before I started the resto of my '36 woodie after other flathead owners said "6v is fine providing you don't want to go out at night!!!"

So I went the whole hog and installed an alternator kit from Macs plus an electronic distributor with the result that the car would start after just a quarter crank... I had some initial overheating probs (with those dire pumping heads) and an elecetric rad fan helped to keep things cool...but that would have drawn too many amps for 6v or a dynamo.

So now I can have lights, fan, electronic fuel pump and the whole nine yards on without running down the battery. I can ever run my GPS, MP3 player and various other 'modern' aids to long distance driving.
 
I know that it's not the traditional way to do things, but I changed my 6v '40 from positive ground to negative ground and installed a 6v one wire regulator. Absolutely no problems staying with 6v. Starts and runs great !

Mike
 
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