Hello. This is my first post here and I'm sure it will be one of many. I just got a 51 F2 which is in pretty good shape for original.. Got it home and after pulling plugs(its sat for a few years) and turned engine over by hand to make sure it was not in a bind, triied to start it with a 12v(I'll learn next time) battery. Engine turned slow a few times then stalled, same thing a few more times. Will change oil and a few more things before trying again. Question is do you think the 12v could have cooked anything in that period of time? By the way it's a flathead v8.
Thanks, Doug

 

If it was stock it was +6v

POSITIVE GROUND !!!!

JOE

 

To answer your question, it likely trashed your regulator (for the reason mentioned), but it wouldn't hurt the starter. If you just want to run it a little, remove the 6v battery, disconnect and tape the wires at the generator, and remove all the wires from the starter solenoid except for the ones for the starter (big battery cables). You'll have to either use the pushbutton on the bottom of the solenoid to crank it, or use the old pliers trick. Run a wire from the hot side of the battery to the (-) post on the coil, and disconnect the wire that's already there to prevent backfeeding the rest of the system. You really should also use a ballast resistor in the hot wire to the coil, or figure on burning the points quickly.

Not so simple, is it?!

 

For me and others can you explain Positive ground? I have been re-wiring vehicles for years but never ran across a P.G. system before.
Is it as simple as it sounds were all positive's go to ground as does the battery post positive and all - loop to their own "Non-grounded" circuit.

Thanks.

Kevin
LFD Inc.

 

Yes positve ground
just like neg ground
Joe

 

Yup, it just that simple. All the old 6 volt systems were positive ground. The change was made to negative ground when the change was made to 12 volts.

 

Well, first things first - Welcome to FTE.

You may have gotten lucky and not hurt anything. Especially if it didn't start up and get your generator turning.

I'd follow the advice above about securing the generator/solenoid wires and installing an ballast resistor just inbound to the coil.

It might have initially tripped your Circuit Breakers - maybe, but they will reset by themselves. Gauges are sensative to over voltage too, so disconnect all of them (gas, oil, and temp) at the senders. Amps will be ok.

You might want to try pulling the plugs and squirting some ATF in each cylinder then turning the engine over for about 5 seconds with the plugs out.

You can use the 12 volt battery (be sure to connect the positive post to the grounding cable, and negative to the starter solenoid "Batt" post -as it should be hooked up already) with the 6 volt starter as long as you don't try and run it under load any longer than about 10 seconds. If you turn it over with the plugs out, it will shoot oil up into the engine and help everything turn more easliy.

Second try, put the plugs back in and shoot a little unlit propane from a plumbers torch down the intake (rather than priming with gas) and it will probably start right up. Remember, the battery will be powering the ignition so I wouldn't run it too long in this shape.

 

Yep. I'm in over my head but I've got it now and gonna make it happen.
Got a new 6v battery today and(now I know about pos. ground). Gonna do a few more things to the motor and try again. Hopefully no 12v damage.
Thanks, Doug

 

Don't want to hijack this thread but I do have a question regarding 6/12 volt...My '54 still has the 6-volt system, and I noticed when I bought the truck home that there were speaker holes cut out in the door panels and stereo looking wires going thru a hole in the glove box liner...Anyway, when I was digging through a box of extra parts that came with the truck, there was this aftermarket grey metal box (about 4" x4" x3")that has an aluminum tag on it...The best I can make out of what the tag says is "inexpensive way to install radio stereo cassette and 8-track players and cb radios in vehicles with six volt negative ground or 12 volt positive ground. Ideal for trucks and foreign cars. Easy to install. 3.5 Amp"...I can't make out what the rest of it says, but I would imagine it's some kind of converter...Anybody ever used something like that to install an updated sound system in an old six-volt truck?

 

Well first of all it probably said 6 volt positive ground or 12 volt negative ground - but that's kind of irrelvant. There are transformers that will allow you to use a 12 volt radio in a 6 volt positive ground vehicle. I've not used one or had any feedback on them.

 

The 6v to 12v inverter works great
I have a cheap am fm radio in glove box
and speaker in stock place
also I put a 12v cig socket
so I can plug in cell or gps!!!!!!
Joe

 

Do they still make them, Joe?...I'm not so sure this one is any good...I checked again, Julie and it does say for vehicles with 6-volt negative and 12 volt positive ground??

 

I think MACS and JC whitney still sell them

 

Very strange - never heard of a 12 volt positive ground car or truck in the US. I wonder of it's for something foreign or maybe a military application?

C&G Ford Parts sells them as well

 

Julie
Since I am old and senile I might be wrong but I think the older MG MGA series cars were 12 volt positive ground. I had a 59 20 or so years ago and seem to remember two 6 volt battery's one on each side behind the seat wired for 12 volts and think it was positive ground.