Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 06-01-2020, 11:53 AM   #1
ButchSr
Junior Member
 
Join Date: Oct 2019
Posts: 2
Default Change to 12 volt negative ground

For several reasons i want to change electrical system in my 1935 Ford Coupe to 12 volt i don`t know where to start can anyone help
ButchSr is offline   Reply With Quote
Old 06-01-2020, 02:13 PM   #2
Mr 42
Senior Member
 
Mr 42's Avatar
 
Join Date: May 2010
Location: Sweden
Posts: 399
Default Re: Change to 12 volt negative ground

Start with a the Generator, you can "convert" the original to 12 V 30A. with a 12V relay
Or buy a new Alternator that looks similar to an original.

Then you have to change the Coil. If you have an original distributor, there is an adapter you can buy so you can mount a separate 12V ignition coil.

Then there is the lamp's that need to be 12Volt.
If you use the original amp meter, you need to switch the cables positions, so it shows charging and undercharging right
Mr 42 is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-01-2020, 02:20 PM   #3
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 14,266
Default Re: Change to 12 volt negative ground

Some information here: http://www.how-to-build-hotrods.com/hot-rod-wiring.html

There are a lot of past threads here on the Barn about voltage reducers for the gauges.
JSeery is offline   Reply With Quote
Old 06-01-2020, 03:38 PM   #4
G.M.
Senior Member
 
Join Date: May 2010
Location: Florida and Penna.
Posts: 4,341
Default Re: Change to 12 volt negative ground

Save your money, get some 1/0 cables and it will spin
like 12 volts. G.M.
__________________
www.fordcollector.com
G.M. is offline   Reply With Quote
Old 06-01-2020, 04:56 PM   #5
drolston
Senior Member
 
drolston's Avatar
 
Join Date: Jun 2014
Location: Williamsburg, VA
Posts: 995
Default Re: Change to 12 volt negative ground

And, there are 12 equivalents for all bulb types in your car. The horn(s) will probably still work but be a bit screechy.
drolston is offline   Reply With Quote
Old 06-01-2020, 05:01 PM   #6
VeryTangled
Senior Member
 
VeryTangled's Avatar
 
Join Date: May 2010
Location: (Not far enough...) Outside of DC
Posts: 2,775
Default Re: Change to 12 volt negative ground

Quote:
Originally Posted by ButchSr View Post
For several reasons i want to change electrical system in my 1935 Ford Coupe to 12 volt...
Hi Butch, Welcome to the FordBarn Forums... I think you'll find some good info here and I'd like to get educated along with you.

I've been pondering the same change on my '35 and I'm really interested in learning what are some of the several reasons motivating you?
__________________
-Jeff
VeryTangled is offline   Reply With Quote
Old 06-02-2020, 06:56 AM   #7
G.M.
Senior Member
 
Join Date: May 2010
Location: Florida and Penna.
Posts: 4,341
Default Re: Change to 12 volt negative ground

The best change would be a 6 volt alternator and larger cables. G.M.
__________________
www.fordcollector.com
G.M. is offline   Reply With Quote
Old 06-02-2020, 07:40 AM   #8
Automotive Stud
Senior Member
 
Automotive Stud's Avatar
 
Join Date: May 2010
Location: New Jersey
Posts: 550
Default Re: Change to 12 volt negative ground

If your wiring is still original I'd just rip it out and put a new 12v universal harness in the car. Speedway has them for about $150.
Automotive Stud is offline   Reply With Quote
Old 06-02-2020, 07:44 AM   #9
MuskegonFlatheadFan
Senior Member
 
MuskegonFlatheadFan's Avatar
 
Join Date: Sep 2011
Location: Muskegon, MI
Posts: 216
Default Re: Change to 12 volt negative ground

Lots of good info in this.
Attached Files
File Type: pdf 6 volt electrical system conversion.pdf (149.9 KB, 39 views)
MuskegonFlatheadFan is offline   Reply With Quote
Old 06-02-2020, 09:24 AM   #10
chap52
Senior Member
 
chap52's Avatar
 
Join Date: Jun 2013
Location: Marana Arizona
Posts: 1,590
Default Re: Change to 12 volt negative ground

That six volt starter will work, but I snapped a couple of Bendix springs during the 13 years I ran one on 12 volts. Chap
chap52 is offline   Reply With Quote
Old 06-02-2020, 09:37 AM   #11
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 6,315
Default Re: Change to 12 volt negative ground

Quote:
Originally Posted by Automotive Stud View Post
If your wiring is still original I'd just rip it out and put a new 12v universal harness in the car. Speedway has them for about $150.
If originality is of any concern to you at all, I would think twice about this solution. As a matter of fact, unless it is a full on "Hot Rod", I would carefully re-consider my original decision.
tubman is offline   Reply With Quote
Old 06-04-2020, 09:42 AM   #12
ButchSr
Junior Member
 
Join Date: Oct 2019
Posts: 2
Default Re: Change to 12 volt negative ground

I have been involved in a fender bender apparently young drivers don`t under stand hand signals so i want to install turn signals,electronic ignition found out you are so limited with 6 volt
ButchSr is offline   Reply With Quote
Old 06-04-2020, 11:42 AM   #13
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 14,266
Default Re: Change to 12 volt negative ground

There are 6v turn signal units available. Might consider a third brake light as well. There are a lot of modern accessories that work better with 12v neg ground.
JSeery is offline   Reply With Quote
Old 06-04-2020, 11:43 AM   #14
flatheadmurre
Senior Member
 
flatheadmurre's Avatar
 
Join Date: Apr 2015
Location: Sweden
Posts: 3,029
Default Re: Change to 12 volt negative ground

Turn signals work at 6v...points ignition may need a light tuneup each spring but seldom fail in a catastrophic way...
If your 6v system is fine just upgrade with turnsignals and be back on the road again...
flatheadmurre is online now   Reply With Quote
Old 06-04-2020, 01:04 PM   #15
KiWinUS
Senior Member
 
KiWinUS's Avatar
 
Join Date: May 2010
Location: Charlotte NC KiWi-L100 available here
Posts: 2,004
Default Re: Change to 12 volt negative ground

6volt OPTIMA battery is you friend.
KiWinUS is offline   Reply With Quote
Old 06-04-2020, 06:08 PM   #16
Karl
Senior Member
 
Karl's Avatar
 
Join Date: May 2010
Location: Manawatu, New Zealand
Posts: 1,172
Default Re: Change to 12 volt negative ground

Quote:
Originally Posted by tubman View Post
If originality is of any concern to you at all, I would think twice about this solution. As a matter of fact, unless it is a full on "Hot Rod", I would carefully re-consider my original decision.
I agree -Optima 6 volt, Decent generator or alternator if you are not a purist, Good cables and Good grounds and there is no need for anything other than 6V-The only benefit I can see with 12V is if you blow a bulb on tour you can buy one easily at any shop. However for me its easier (and cheaper) just to carry a couple of spare 6V bulbs -which I have never used ! I have turn signals on mine as well as an AM /FM radio all running well on 6V -Karl
__________________
Such a fine sight to see-Its a Girl, My Lord, in a Flatbed Ford slowin' down to take a look at me.
Karl is offline   Reply With Quote
Old 06-04-2020, 06:28 PM   #17
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 6,315
Default Re: Change to 12 volt negative ground

Plus, I make a device that alows you to run any 12 volt negative ground commonly available tachometer of a 6 volt positive ground vehicle. i am also running a device that alllows just about any 12 volt negative ground accessory to be run on 6 volts positive ground. I have a prototype that allows a GPS, Bluetooth for my cell phone, a backup camera, and a CD player to run in my '51 as we speak.
tubman is offline   Reply With Quote
Old 06-05-2020, 10:58 AM   #18
whizzernick
Senior Member
 
whizzernick's Avatar
 
Join Date: Jul 2013
Location: Hayward Ca
Posts: 466
Default Re: Change to 12 volt negative ground

I have run my restored 1933 roadster on 12 volt for over 40 years.
same original coil - starter & generator. the generator will charge (just adjust 3rd brush to wanted amp charge ) I use an additional ( common 12 volt ign resistor ) for ign
change bulbs to 12 volt . horns work better . switch wires on am meter . I use a small 12 volt battery in a battery box I make ( also sell ) that makes the battery look like a 33 battery. My lights are brighter --- my car starts faster all in all best of both worlds.
whizzernick is offline   Reply With Quote
Old 06-05-2020, 11:32 AM   #19
4t8v8
Senior Member
 
Join Date: Nov 2011
Location: NW Arkansas
Posts: 501
Default Re: Change to 12 volt negative ground

There is a reason Detroit and other car manufacturers switched to 12 volt many years ago. I switched my '48 30 years ago and never looked back. Wouldn't even consider 6 volts.
4t8v8 is offline   Reply With Quote
Old 06-05-2020, 11:39 AM   #20
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 6,315
Default Re: Change to 12 volt negative ground

Quote:
Originally Posted by 4t8v8 View Post
There is a reason Detroit and other car manufacturers switched to 12 volt many years ago. I switched my '48 30 years ago and never looked back. Wouldn't even consider 6 volts.
Yes there is : high compression, large displacement OH V8 engines. They did try to stick with 6 volts for quite a while before they decided they had to change (e.g. Oldsmobile through 1951). Smaller gauge (and therefore cheaper) wiring also had something to do with it.
tubman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 01:43 PM.