Switching from 6-volt to 12 volt.

[Bob Ritter]

When switch from 6-volt to 12-volt, does the system still remain a positive ground? I see a lot of folks have made the switch and was thinking about doing the same.

Thanks, Bob 

[DJ194950]

Your choice.

 

Can be either. Pos. ground is most common for accessories like 12 radios, CD players,  etc.

 

DJ

[Plymouthy Adams]

12 minutes ago, DJ194950 said:

Your choice.

 

Can be either. Pos. ground is most common for accessories like 12 radios, CD players,  etc.

 

DJ

 

I think you may have meant to say NEGATIVE ground is more popular as it has been the standard for majority of automakers since 1956..some changed a bit later 

[Bryan G]

I've seen some half-hearted and botched switchovers. I'd say to start by asking, why are you switching?

• you want to run a lot of modern technology that requires 12v.
• you are installing a later model powertrain that isn't compatible with 6v.
• Joe Blow told you 6v is junk
• your 6v battery keeps dying/starter spins slow/headlights are dim.

For the first two, yes, you are probably right to make the switch. In that case I think the right way to go would be negative ground as that would be what all modern equipment expects. I can think of no reason to go positive ground in that situation.

 

For the second two...Joe, with all due respect, doesn't know what he's talking about. And if your 6v system isn't working, you could actually just fix what's wrong with it. Many of us put tens of thousands of miles on 6v systems without these problems.

[DJ194950]

20 hours ago, Plymouthy Adams said:

 

I think you may have meant to say NEGATIVE ground is more popular as it has been the standard for majority of automakers since 1956..some changed a bit later 

well you are correct! I need to read my post before i post! ?

 

DJ

[mattimuss]

I too am interested in converting my '41 from the 6V pos ground to a 12V neg ground system.

 

I have done several searches though the topics and have found lots-o-info, but not one "group approved" guide to complete this process.

 

Is there one that can be "pinned" to this forum for easy access for "novices" like me?

[greg g]

Put in a 12v battery but leave the negative cable disconnected.

 

Turn every thing on

Connect the battery

Now replace rvery thing that no longer works or is smoking 

[Los_Control]

Just now, greg g said:

Put in a 12v battery but leave the negative cable disconnected.

 

Turn every thing on

Connect the battery

Now replace rvery thing that no longer works or is smoking 

I had to break out & laugh about that ... really is true though.

Most of the gauges etc do not care ... mainly the lights. I think the radio is the biggest problem.

[Sniper]

7 hours ago, mattimuss said:

but not one "group approved" guide

 

Not going to get one of those either, the responses so far ought to be a clue.

 

You have a group of people here that think you should keep your car the way they want it.  Then you have a group of people here that think it's your car, build it your way.

 

I converted my 51 to 12v primarily to get headlights that work better than hanging a Zippo lighter out the window.  Now there are some that claim there are 6v headlights that do work good, I disagree. 

 

All your bulbs will need to be changed to 12 versions.  If you aren't sure your local NAPA can take the 6v ones and find the 12v versions, I did that for a few I had.

 

Gauges, other than the lights in them and the fuel gauge, don't care they are mechanical ones.  Fuel gauge can be handled by a Runtz Resistor, which is not a resistor, btw.  Though I think your 41 in particular won't care and doesn't need it. 

 

Depending on options you have and the year of the vehicle you may need to address the wiper motor (if electric) and the heater blower motor (if you have a heater).  I found a 12v blower motor that physically fit where my 6v one was.  Aftermarket turn signal switch won't care, but you may need a 12v flasher.

 

Finally, there is your radio, if you have one.  If it currently doesn't work consider an AM/FM 12v conversion.  If it works and you are satisfied with AM only you may need a 12v to 6v regulator of sufficient capacity.

 

Then there is how you create the 12v.  I went with a typical 70-80's Mopar alternator and regulator setup.  Just mimics the 87 Diplomat system as it was the highest rated, 78A, "normal" looking Mopar alternator, imo.  No one wire, no chrome, no looks like a generator but puts out 12v.  just cheap dependable OE design charging system.

 

Finally, there is the battery and cables, group 24 fits many places.  Group 27 is physically bigger with more capacity, but I haven't needed one.  For cables I just bought new ones from Rock Auto of the appropriate length and added a battery to body ground strap from the negative terminal to my radiator core support.

 

I think that covers it, any questions ask.

 

[DJ194950]

Posting a how to on more permanent areas that last would be sacrilegious to some regulars on the forum.

 

They hold to if it worked 50-60 years ago it must be good today.

 

Nothing wrong with that in Their cars.  Others have other ideas that do not follow those. Count me as one who believes that it is yours to do as you please as long as your changes do Not destroy the original character of the vehicle.  Now that is My opinion!  ?? Please no other brand motors installed.  Which I once did before I knew any better!  ?

 

DJ

[Semmerling]

After working with 6volt for 2 generations, the 3rd switched over to 12v a while ago. We used a "5th Avenue" 12v kit. 

 

I think Sniper's response above properly describes the process and the general feelings about this conversion. It's a personal choice.

 

All the original 6v related parts have been rebuilt/restored and set aside for anyone who would choose to place them back on the car...which just quietly mumbled "what?!?" 

 

Edited April 24, 2022 by Semmerling