I know I have asked several questions on this before, but still a bit confused. Have been ill the last two weeks die that horrible coughing virus, so have not been in the shop. Hope to be back out there this week. Will be installing new battery cables and some wiring to fire up my 1949 Ford Coupe Flathead V8 positive ground. My understanding is that I hook up everything basically backwards from a negative ground. Is this correct ?? Thanks
Fords up to and including 55 were 6 volt positive ground. 6 volt cables are larger than 12 volt.; Almost twice the size. Using 12 volt cables or what’s usually available at auto parts stores will cause nothing but headaches and disappointment.
Thanks, I am aware of that. Bought a complete set of 6 Volt cables from Shoebox Central... Still need answer to my question though !
Here is some good reading material: https://fifthaveinternetgarage.blogspot.com/2017/06/changing-your-electrical-system-from.html
For Positive ground, the + side of the battery is grounded to your engine, the - side of the battery will go to the starter solenoid. If nothing has been changed prior, that’s all you should need to do.
Remember, if changing from neg ground to pos ground ( or the other way around) you will need to swap the wires on the amp meter or it will read backwards.
Let me add one thing to my post above, I meant to, but got a radio call at work and forgot. Most battery cables you purchase are red and black, red for positive, black for negative. If using a post battery, it’s very likely the red cable on the positive (+) post on the battery will go to ground and vice versa. I bring this up because most assume black-ground, red-positive. But the post clamps are two different sizes, so don’t spread open one, and try to tighten the other to fit on the battery posts. Hope that made sense for you.
In reading the OP post, I think he is leaving it 6V positive ground and just asking if everything he hooks up needs to be hooked up backwards. A 49 Ford wiring diagram is the best way to confirm.
As the wiring is at the moment before you change any wiring is it wired for 6v positive ground. or negative ground
Appreciate all the replies. Understand them. I am asking about hooking up the coil, gauges, headlights and other things...... do I just do it backwards from normal negative ground ?
Use one of the old style braided “cables” on the ground to avoid confusion wit modern red / black color coded cables. Since you are getting cables from a flathead specific source, that’s probably already in the works.
Don’t mix the words positive and ground together in a sentence. That way it will free up the mind to put the (+) red to the chassis and (-) black to the starter.
In answering your last question, the basic answer is yes. As posted previously, a wiring diagram will help you greatly. Think about it this way- every "lead" you hook to something needs to be negative, and every "ground" needs to be positive. Lights and gauges (except ammeter) do not care about about the polarity. The ammeter and coil will need to be wired correctly, as does the starter. Crossing polarity among different things will be where the issue will arise.
Actually if you are wiring up a positive ground vehicle and leaving it positive ground nothing is wired up backward. it came that way. It is backward if you have never worked on a positive ground vehicle.
It's all in the link I put up in post #4. Here it is again. Have a read. It is very helpful. https://fifthaveinternetgarage.blogspot.com/2017/06/changing-your-electrical-system-from.html
People always seem to confuse positive and negative with hot and ground. Not so. Like when jump starting a positive ground car. They have a hard time hooking cables up, fearing hooking "Positive" cable to "Ground". Just hook positive to positive to positive and negative to negative and forget about negative "always goes to ground". Or like my left handed son, he always does things backwards! Dave
The Jalopy Journal
