6 volt. Positive ground?

farmboy

farmboy

Senior Member
When my throwout bearing gets delievered, and I get the engine put back in Pop's 36 1.5 ton, i'll be wiring and plumbing everything. I've been hearing of Positive grounds on some of these 6 volts. We had an H farmall on the farm that was 6volt positive ground till my grandpa switched it to 12, now it's a negative ground. Where these trucks positive ground, and how can I tell how it needs to be when I get to that point? thanks again, Bret..
 
All Fords through 1955 were 6 volt positive ground. I believe it has something to do with positive ground being more efficient for 6 volts. That being said, if you plan on keeping it 6 volt, also keep it positive ground. If you want to convert it to 12 volts, you probably should change to negative ground, because that's the standard (except for some oddball vehicles from England and Czechoslovakia).
 
It was originally 6 volt positive ground. Most people change to negative ground if they switch to 12 volts. Almost all modern cars are 12 volt negative ground. I can't think of any that are not except the electric vehicles and I don't know what they are. The advantage to 12 volts negative ground is that you can run all of the modern electronics. Chances are good that it is 6 volts positive ground. The positive post on the battery is slightly larger and if that cable/strap goes to the frame that should confirm it. Hook the battery up that way and the ammeter should show a charge.

Charlie Stephens
 
A slightly different topic, is it currently wired or will you be adding the wiring? If you are adding new wiring keep in mind that 6 volt systems carry more current than 12v systems and require heavier wiring size (gauge). You can not use the normal battery cables and starter cables you find in most auto supply stores. You sound like you are familiar with farm equipment you might be able to find the correct cable sizes at a supplier that also supplies older 6v farm equipment.
 
The way I heard it was Ford was friends with Edison and it was Edison that convinced Ford electricity flowed "better" through a positive ground. It was after the bigger V8's and higher compression came in that 12v negative ground became standard, somewhere in the mid 50's.
 
That Positive ground cable will go to a tab on the universal joint housing using a 5/16 - 24 bolt for best ground.
 
Tractor supply carries the bigger cables for 6 volt. (1gauge) in Black or red various lengths. Also had the woven ground strap. Used them on my '49 F1 with new motor and it cranks like a champ.
 
You must log in or register to reply here.
Back
Top