6 or 12 volts?

Vanspeed

Vanspeed

Well-known member
I recently picked up a 48 f-1. It is an all original truck. Last owner cobbled up some wiring and has a 12 volt in it. I want everything to work on this truck, heater, gauges, etc. it is only wired to run off the 12 volt. Should I go back to 6 volt? I want to re-wire the truck with original style wire harnesses. I down care about dimmer lights as this isn't going to be driven at night that much. Mainly Sunday lumber yard runs and general farm use.
 
I believe six volt is plenty
Every thing in the original truck should work on six volt. Make good grounds and your lights will be okay. These trucks will last forever.
Bruce
 
Hi there, If all the electrical equipment is original 6 volt such as the generator, starter, ignition coil and lights then leave it 6 volts which will be fine. If he had a 12 volt battery in it lets hope the original ford gauges have not been overheated or damaged. Yes rewire with a new wiring harness for reliability. Fit a 6 volt OPTIMA battery in it, they are the best. Regards, Kevin.
 
Do the gauges still work? I thought putting 12 volts to the originals would damage them pretty quick. If it has been converted to 12 volts does it have a 12 volt charging system? Newer alternator installed? Most of the six volt Fords I knew seemed to crank just fine on 6 volts. With the exception of my 52 Merc which just does a slow grind on 6 volts and is crying out for 12 volts of cranking power.
 
Hi Jeff, I went with a 12 volt system and use an alternator, you've indicated the guy you got it from has it running on a 12V. I like the 12V set-up ( some people do some don't ) and there are kits to convert the gauges to run on 12V and they are cheap. Basically just inline resistors to reduce the 12V back to 6V where required. Your starter will work fine on 12V as it is heavy duty ( many of us do and it works fine ) and spins twice as fast as with the 6V, a big advantage for quick starts. The stock 6V wiring is more than adequate for the 12V so any new stock harnesses you buy will work fine.
Here are some of the things you have to worry about if he didn't set it up right when he converted to 12V. All the lights will be 6V and burned out. You need to go 12V on all the lights, ( I think the 12V lights are brighter ). You will probably have to put a resistor ( should be in the 6V to 12V conversion kit ) on your heater motor to reduce the 12V to 6V as it's not as heavy duty as the starter motor. Your amp gauge can run on the 12V as it is only measuring Amps. Temp., fuel, and any other gauges which have electric sending units if used with the 12V are already fried and will need to be replaced.
Working on them is half the fun so enjoy the trip.
 
I've run a 48 F1 for over 10 years as a daily driver. Converted to 12V when I rebuilt it in '01. I think it makes sense for a daily.

As Tony said, use a voltage reducer on the gauges like runtz (one per gauge) or one big enough to reduce all at once. That's what I put inline.

Starter and generator will work on 12V without changes, but when you get the chance, rewire for 12V.

Scroll down to converting 6 to 12 and follow Patrick's advice. Worked for me.

http://www.patricksantiquecars.com/articles.html
 
I put new wiring in my 52 f1 and kept it 6v. Everything works great. The only downside with 6v is if you leave the lights on and need a jump start.
 
You can jump start it from a 12 volt vehicle. Just make sure ALL the lights and the radio are off. Ask me how I know. They usually start real quick that way; just don't crank and crank and crank and .....
 
I have an old tractor with a 12V battery in it, (not converted just a 12V battery) gotta have it for quick starts in the winter and love the response. Like you stated, keep original wiring and someone can always convert back. My car has a 6V and if it sits too long forget it!
 
All this talk about how fast it spins??? If it needs to spin to start there are other problems. It should start with a hand crank on the first or second turn. 6 volts systems need large (2/0) cables with good soldered on end terminals. Battery connections must be clean and tight along with solenoid, starter foot switch and starter. The starter also needs a good ground. The metal surfaces where the ground cables contact the body, engine or frame need to be cleaned down to shinny metal and electrical grease applied between terminal ends and cleaned metal. This will prevent corrosion at the contact areas. Use the grease on the battery also. Keep the battery fully charged and if the engine sits for a long period of time use a shot or two of starting fluid. I have a number of 6 volt Fords and very seldom ever have a problem even after sitting a year or more. As far a doing a lot of driving I like the 6 volt alternator as long as they charge at idle with a stock size Ford pulley. I made 7 6 volt alternators using a Nippedenso 12 volt alternator with an adjustable 6 volt regulator and reverse polarity diodes mounted in 39 type generator housings. G.M.
 

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I have Flatheads that I've kept 6 volts positive ground and Flatheads I've converted to 12 volt negative ground. There are pros & cons to both. If you rewire with the heavy OEM style wiring, you can run either 6 or 12 volts. If you rewire using a modern wiring kit you may not be able to run 6 volts without having some problems. If you want to retain the OEM 6 volt system, make sure all the grounds are clean and tight and make sure your battery ground cable is heavy enough for the 6 volt system. If everything else (in the electrical system) is up to par, you'll have no trouble running 6 volts. Ultimately, the choice is yours. I'd weigh the pros & cons relevant to your needs and act accordingly.
 
There's a lot of proponents of 6 volt on this board. I converted my '48 to 12 volt. I had kept it 6V for years, rewired it with a Dennis Carpenter kit designed for 6 volts, so the wire is a little more heavy duty than needed with 12 volt.

After having switched, I personally wouldn't ever go back to 6.

Here is a thread I posted you might find useful when I was doing the conversion:

http://www.fordbarn.com/forum/showthread.php?t=131960
 
The gauges have resistors on them but they do not work, the wiring to the headlights and tailights is gone. It is just a plain mess under the dash. It fires pretty fast with the 12 volt so I imagine it would fire just fine with the 6 volt too. Seems to be the majority of going back to 6 volt which is what I was thinking about.
 
I have a '48 F-1 that is very original - and is 6V. I'm old enough to remember when all cars were 6V and no-one thought a thing about it. We thought the shift to 12V in the late '50s was a scam to save money by using less copper. My truck works fine. Lights are perfectly bright. The only caveat is the one usually mentioned on this forum - use heavy copper battery cables and be diligent in seeking out bad grounds. Keep it 6V!!!
 
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