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12V Vs 6V


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So, I am deep into the thinking stage on my daughter's 49.  The motor is running on 12v now just off the battery.  I have read and read and for the life of me can't decide if I need to go 12v or leave the truck 6v.  I will put all new wire in it any way.

 

Can someone please tell me which way to go.  If I go 12v the hidden radio will be a breeze, but everything else will be resistors and other electronic do dads all over. 

 

What is the reasoning for changing over?  My other thought, not to deaply yet is...  Can you throw two 6v batteries in and run  some stuff off 6v side and series them for 12v on other stuff?

 

Confused and thinking.

 

By the way this forum is great!  Two weeks and I have already sourced lot of info and a fender, air cleaner, and badge.  Thanks Kevin.  A radio and gas tank will be here today.

 

Thanks,

Andy

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Andy,

I left mine 6 volt as all the parts are still availble.

I did buy a 6-12 volt converter to run a modern stereo.

http://www.ebay.com/itm/6-12-Volt-Inverter-Voltage-Booster-Converts-Positive-Negative-GND-/230982850729?pt=Car_Audio_Video&vxp=mtr&hash=item35c7a698a9

 

Also, a 6 volt system can be jump started with a 12 volt system.

 

Keven

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Your thinking is right. If you do a full 12v conversion you'll need resistors for your coil/ignition system, fuel guage, and fan blower motor. And if you have electric wipers you'll need something for that too. You'll also have to change out all of the light bulbs for 12v versions. It's a little more work up front but, as you say, adding modern accessories like a radio is then easy. And if you ever need a jump start there are no worries about connecting to a 12v car.  

 

If you leave it 6v positive ground you can still add a stereo, as long as you're not adding a big amp to go with it. I have a voltage convertor in my truck that converts my 6v + ground to 12v - ground. I have a stereo connected to that along with a couple of power outlets for my GPS and/or cell phone charger. I even use the power outlet to power my timing light when doing tune-ups. With all new wiring, proper battery cable size, and a good battery and starter I have no issues starting the engine or using the headlights at night. Some people think you need 12 volt headlights to be able to see at night, but a good functioning 6v system will offer just as much light using similar type sealed beam headlights.

 

I would advise not to use the two series 6v idea. It may work but you'll have charging issues and shorter battery life due to imbalanced loads between the two. The charging system will over compensate for the battery with the heavier load and will overcharge the other one. I've seen this happen many times when operators tap off on one battery of a 24v system to power a radio.

 

Merle

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My truck had no usable wiring at all.  Since I was redoing all of the electrical, I decided to go with a 12v system.  Super easy to convert if you are replacing everything.  I did the GM alt, with a resistor at the coil.  Havent hooked up any of the original guages yet, but a runtz for the fuel guage is 3 bucks on ebay.  Now I can install all modern electronics with no issues.  I have istalled an elecrtic fuel pump and fan. 

 

The purests say stay with the 6v, I'm a fan of the 12v. I think it just boils down to a personal choice, and what you are comfortable with. Either way you wont be wrong.

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Can someone please tell me which way to go.  

Thanks,

Andy

I dont believe anyone can tell you what way to go. That choice will be yours.

 

When I bought my car the prior owner did a half fast 12 volt conversion. Stuck a 12 volt battery in the car and replaced the headlight bulbs only. The charging system did not work. So I converted all the rest including a GM alternator. I also have an electric radiator fan and I do not use a belt driven fan. I also installed some aftermarket 12 volt LED tail and brake lights.

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yes you can use twin 6 volts batts and have 6 and 12 system together with only a 12 volt dynamo..that will require some change there, it wall also require periodic rotating the batteries for longer life as it is understood by me in reading it does have an effect on the charge capacity one better than the other..also you will have to chose negative ground..you may want to visit some on line sites that are dedicated to earlier farm tractors as this was a popular setup for them...

other than that..your call 6 or 12...6 volts will require heavier wiring on the harness when made vice that of 12..12 volts will allow more creature comforts and accessories in the car..cell phone changer, GPS and such..of course stereo and other techy things younger folks like and seem to must have...also if she is out and finds herself with a flat battery it is a snap to get a jump with 12 neg as opposed to finding someone who knows how to do it proper with 6 and 6 volt pos...just food for thought..

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12v Chevy truck "1 wire" alternator and the biggest 12v battery Walmart carries excluding trolling motor/RV deep cycle versions. The stock parts are "cute", and they do work, but if you break down in the backside of b.f.e. (or anywhere in Memphis) and you're running stock electrical parts, hope you made sure your AAA membership is paid up...

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Thanks, guys.  I like the idea of leaving it stock.  But, I hear ya Skruffy.  Even though SHE will know how to jump it, how many "helpfull" guys of any age are going to take the word of a 16 year old girl.  

 

So, If I go 12v is there not a simple way to pull 6v off of it for the gauges and heater.  I can't believe in our "electronical" age there is not a way to simply drop the stuff down at one spot.  As Keven has stated there is a $60 fix to go from 6 to 12v.  Would be nice to go back the other way.

 

I guess I will go 12v since we have to put everything back to new anyway.  I pulled the heater Saturday night.  If there was any thought of not going with new wire it is gone now.  Just touching the heater wires gave me a whole length of bare wire. :)

Edited by Dajudge
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Here's a DC to DC converter on ebay rated for up to 15 amps. Most are fairly small, but if you want to run the heater motor and/or wiper motor along with the gauges and etc, you'll want one with a higher output.

http://www.ebay.com/itm/12-VOLT-to-6-VOLT-HIGH-POWER-AUTO-VOLTAGE-CONVERTER-/260788003463?pt=Car_Audio_Video&hash=item3cb82d2287#ht_605wt_958

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I rewired mine for 12 or 6 and left it 6 with no regrets. But then I'm not a radio fan. Referring to your daughter or any other teenager, don't they all listen to their music via some electronic device? At 16 she is in college in two or three years. So I say, consider what you will need three years from now.

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I converted my 1 ton to 12v several years ago when I was rewiring it.  I did the same w my 36 Plymouth.  The 49 2.5 ton is still 6v pos ground, and I may leave it that way. I do like the way that 12V spins over the starter, and I've never had much luck w 6 volt batteries lasting very long.

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I converted to 12v years ago and have not regretted it.  I switched to a 12v generator at the time but I'm redoing the truck now and have installed a mopar alternator of 74 vintage.  The bulbs should be changed anyway and used a resistor for the fuel gauge.  

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I converted my 1 ton to 12v several years ago when I was rewiring it.  I did the same w my 36 Plymouth.  The 49 2.5 ton is still 6v pos ground, and I may leave it that way. I do like the way that 12V spins over the starter, and I've never had much luck w 6 volt batteries lasting very long.

 

I typically get 4 to 7 years from my 6v batteries. The '33 only has 5.5:1 compression ratio so it might be easier to spin than the later cars. The 6v starter spins it over quite nicely.

 

To me the biggie is how badly you might want to put something like air conditioning on the car or a 1,000 watt sound system. Those would be really tough to do on a 6v car. But for basic functionality (starter, lights, etc.) the 6v system, if in good repair, works just fine.

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Thanks, guys.  I like the idea of leaving it stock.  But, I hear ya Skruffy.  Even though SHE will know how to jump it, how many "helpfull" guys of any age are going to take the word of a 16 year old girl.  

 

So, If I go 12v is there not a simple way to pull 6v off of it for the gauges and heater.  I can't believe in our "electronical" age there is not a way to simply drop the stuff down at one spot.  As Keven has stated there is a $60 fix to go from 6 to 12v.  Would be nice to go back the other way.

 

I guess I will go 12v since we have to put everything back to new anyway.  I pulled the heater Saturday night.  If there was any thought of not going with new wire it is gone now.  Just touching the heater wires gave me a whole length of bare wire. :)

Personally I do not think you have read all that is out there on this..even 12 volt cars of the 60's and 70's used 6 volts for the gauges
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I went 12v with my 48. It wasn't that bad of a process. If I had did a little more research before diving in I could've done the full swap in an hour. I kept all the 6v parts an bulbs. If anyone ever offers the right price and would like it to be 6v, I can make the swap back no problem.

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If i was not doing a motor swap on my '52 i would leave it 6 volt positive ground the way it is. Its really not a big deal and you can still get the parts for the 6 volt system. Just make sure you use appropriate sized wiring as it will carry more current than a comparable 12 volt system. Thats just my 2 cents...

 

-Chris

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Personally I do not think you have read all that is out there on this..even 12 volt cars of the 60's and 70's used 6 volts for the gauges

Gee, I think your right.  That's why I was asking for input.

 

Thanks for the answers guys.  I think I will investigate the 12v to 6v converter for the gauges and see what to do about the heater.  

 

I appreciate everyones time.

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One stop shopping for the 12 to 6 drop parts? Chev's of the 40s, Sacramento Vintage Ford, Speedway Motors, etc. Or pull the voltage reducer off the back of any 60s or 70s Ford or Dodge in the nearest junkyard. Take notes on what was hooked to what side of the unit and whether it had an ammeter, a voltmeter, or idiot lights. You need an all gauge version, but, if your engine is a stone stock 40s flattie, the temp and oil pressure are mechanical. I do have an electronic oil pressure sending unit and temperature sending unit in the late 50s 230, no idea if they work, will likely be replacing the gauges/sending units anyway.

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I found this diagram when I was researching mine, plus an answer or two from the guys here.  It's pretty straight forward.

 

The resistor for the coil is available in any auto parts store.  The ones for the guages are 3.00 on ebay.  They are called a "runtz". 

 

post-4696-0-85399400-1369229504_thumb.jpg

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I much like my 12 volt 1955 Fargo pickup with 251 engine. I have a Delco 10SI 1 wire alt, balast resistor for ignition coil( simple as it gets), all 12 volt bulbs. I could either use the heater blower  with a universal 12 volt motor, but used  a 50 watt 1ohm resistor, this drops the voltage no problem, it gets warm but no big deal. I have no installed a Runtz for the gas gauge yet.

I just love 12 volt engine starting, lighting is a bit better, nice to have modern stereo and tach easily wired in, without having to use a voltage invertor or seperate 12 volt power source.

If you are at the beginning, I vote for 12 volts.......

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