6 volt, positive/negative ground ?

I'm working on my 46 Ford 2 dr. sedan
http://www.jalopyjournal.com/forum/showthread.php?t=825516

I thought it should be positive ground, but it has newer battery cables and is negative ground.

battery was dead when I bought and has negative post to ground. I used a 6 volt charge to start/jump and can get engine running, but I can't get any voltage readings about 3 volts while running.

the dash light work and a few other things with the battery hooked up negative ground. also car has been sitting for 40ish years...

i'm buying a new 6 volt battery today and wonder if the generator isn't working because battery is negative to ground.

how do I tell correct what to hookup.... it appears to have factory voltage regulator/generator etc.....

 

I believe only british cars were positive earth

 

Try polarizing the generator. Google it.
I saw a 51 Nash yesterday that was positive ground.

 

My '55 Ford is 6 volt positive ground. Make sure you have heavy gauge battery cables, need to be almost 2x's thicker than 12 volt cables. I had new cable, but wrong size and had starting/battery problems.

 

All Fords (and some others) were positive ground until 1956.

 

Yep, Ford was positive ground, 6 volt until 1956 when they changed to 12 volt negative ground.

 

Mopars were too.

 

Beyond polarizing the generator you need to determine if the coil is original Ford (positive ground) a correct replacement, or an in-correct ( now correct for your current polarity) negative ground replacement.

The car will start and run with wrong coil polarity, but will have mysterious miss and reving problems at rpm's above mid to higher range.

 

Ford products were all pos (+) ground (earth) up to, and including 1955. 1956 saw everyone (American) going to the 12 volt neg (-) ground standard.

I'm sure that made accessory mfg happy, to be making things the same !!

4TTRUK

 

check your ground

 

I would think the starter would spin the wrong direction with a backwards battery.

 

nope... starters only spin one way

 

How ever most blower motors will, hows your heater work?

 

curious.....i count 4 caps on that battery?

 

8 volt battery with 4 caps and two volts per cell under each cap.


53 F-3 check the leads on your coil. The + side of the coil should be connected to the distributor if the hookup is correct.

Ford 6V was + ground as was Mopar 6V and International 6V through 55 at least.

Even if it starts and runs with neg ground the amp meter will work backwards if the guy who put the battery in backwards didn't reverse the wires and the gas gauge probably won't want to work.

I'd put it in with + ground, make sure the coil is hooked up for + ground and go from there.

You can find the information to polarize the generator on the net or in an old shop manual. It's too late and too cold an I'm too tired to go out in the garage and dig out the book tonight but I'll try and remember in the morning.

 

I replaced the 8 volt (wont hold a charge battery) with a new 6 volt, with negative side grounded. it starts, idle and drive pretty good. I do think it has some higher RPM issues, but it needs new wires also (I can see plug wire arcing in a few places to ground)

I will check everything tomorrow that's been mentioned, thanks a lot.... i'll post findings

 

here's a pic of how the coil looks now, the DIST (I assume is + ground side via distributor) lead is hooked up to the distributor and the BAT lead is going into a very brittle old wiring harness. also has condenser hook up

currently with battery negative ground and engine running the generator isn't charging (not increasing battery voltage while running)

wish me luck, i'm going to hookup battery positive ground and see how she works.....

 

That is a positive ground coil so reversing your battery and polarizing the generator should do the trick and give you correct guage readings as well.

 

thanks a lot, I installed new battery positive ground. car starts runs drive etc... now the oil pressure and temp gauges are working...(amp gauge is in middle)

voltage at battery is the same with engine running or off, (but I did fully charged battery prior to installing)

going to get the lights, heater motor working and "polarize" generator and regulator next)

 

Before you do any thing else, with the ign off, turn on the head lamps. Which way does the amp gauge move??? If it moves to the discharge side, you should be good to go, it it moves the other way, your leads on the ammeter need to be switch to go back to pos ground. A quick test of the genny, by grounding the field terminal with a temporary jumper wire, the amp gauge should peg to full charge with the car a high idle .

The amp gauge reacts to the voltage regulator and the load. If your battery is fresh and fully charged, the VR will only work the genny till the battery is back to normal. So with only the ign on, the genny will only need to charge at a rate equal to the draw. so it should stay in the middle in normal conditions.

 

Be sure you have the battery correct cables for a 6 volt system. They are heavier than the cables used for a 12 volt system. The small cables will get hot and leave you wondering why the engine turns over so slowly.

Charlie Stephens