Need help with 6 volt positive ground.

I've been a Ford guy all my life, never owning one older than '63. I just picked up a remarkably complete '51 Chevy, right down to the air cleaner, spare tire, jack, etc. I know it is a six volt system, however it had a 20 year old Ford twelve volt battery (group 78, I think) in it, BUT not hooked up. The voltage regulator is still six volt. I got the correct 6 volt battery yesterday, but I'm afraid to go too far. I've been told mine is a positive ground car, but the starter cable wire has a terminal end opened wider for a positive battery terminal and the block cable has a terminal end smaller for a negative battery terminal. So in theory my positive cable should go to the block, the negative to the starter, but I'd like to confirm that for certain. I have the head on the bench to free up a couple of sticky valves, and to find out why the crank won't turn. Marvel mystery oil and a flywheel wrench solved that, so I want to try the starter. Just tell me for sure it's positive ground, and from there I'll see if any damage was done to the electrical system.

 

It is not a positive ground. Negative should go from battery right to by the thermostat housing.

 

Is ground strap braided and more toward the front of the car? Should be, and positive toward rear of batt tray and right down to the solenoid

 

Fords from that era are positive ground.

 

Old Mopars from that era are as well. right up to 1955.. Positive ground..

 

And TV sets were black and white Stay on point.
Your Chev is negative ground, as was pointed out. Even if you hook it up wrong, you wont hurt anything except, maybe, the radio.

 

X2


Ray

 

It must be a common misconception because my 50 was hooked up positive ground. It's negative.


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51 chevy negative ground positive to the starter

 

Hook it up wrong and your horn will suck instead of blow ha ha ha not really funny joke.

 

If you connect your starter motor EITHER WAY, it will go in the same direction because the armature and field wires are connected internally. If you reversed either, it would reverse rotation.

Generators and regulators; same story. They can be either pos or neg gnd as there are no diodes or solid state devices inside.

The heater motor will go backwards if connected wrong if it has permanent magnets.

Heat-activated Fuel and Temp gauges don't care which way the batt is connected. If the radio has an original mechanical vibrator, it can be wired either way. Most clocks were solenoid-wind, so they don't care, either.

Magnetic meter movements will try to go backwards (if you have any).

Some folks ran their batteries backwards for years, and never knew it. Check the books for the correct polarity. - Dave

 

Thanks guys, great info. I guess now I need to worry if it was run on 12 volts, but visually the wiring looks to be in great shape. Oh, it has no radio. Or turn signals. It's about as basic as it gets! I'm taking baby steps with this thing, and so far so good. Engine's freed up and looks decent enough inside, and the valves now all snapping shut smartly. I'm glad I pulled the head - no bent pushrods or valves to replace! Hope my horns blow instead of suck! BTW, the H.A.M.B. seemed to be well represented at Billetproof Saturday.

 

How come I can't find a fuse panel?

 

'cause there ain't none..........



Ray

 

Yep, mine had an add on glass tube type panel right under the dash drivers side. Rip all that crap out, go 12 volts and save the headaches. Well worth the time and money. Look into the 9+3 harness from Rebelwire, I used it in my car and it is great.

 

actually on the Delco regulator it will say which ground it has on the side by the number and the regulator points will fail quicker if reverse polarity
OLD and not totaly senile YET

 

12 Volts won't hurt the wiring...it's larger gauge than 12 volt systems use. (heavier gauge carries more amperage for less resistance at lower voltage)

 

The only GM vehicle that was positive ground is a 6 volt GMC truck and dont know for how long they were made that way.

 

wanna know if your car was set up for 12V? Look at the headlight and tail light bulbs. My avatar had 12V bulbs everywhere

 

You just beat me to it.

Your car may have been converted to 12 volt. Check the bulbs and the heater motor. Twelve volts will work just fine on a six volt starter motor, but it will quickly burn out six volt lamps. - Dave

 

Thanks again to all who responded. The regulator's aftermarket, but I'll check it. The headlights work fine on 6 volts, as does one taillight. The other's dim, so likely a 12V bulb. I've got a service manual headed my way (good old eBay), so I shouldn't have too many more dumb questions. The dash lights don't work, that's why I was looking for fuses. I'll worry about that junk once I get the engine running, and rebuild the hell out of the brakes. Can't wait to get this old tub of shit on the road!

 

Have any pictures of the car?