hi there im new here i got a 1948 dodge custom that i dont understand the positive ground stuff i just was able to start it 4 the first time in 30 years n i did it with a 12 volt battery then i bought a 6 volt battery n it doesnt turn on the crank is real weak my negative post seams to be connected to the block under the generator n the positive goes to the starter solenoid, when i put my batterys the 6 volts n the 12 volts i put it like a normal negative to the - n the poss to the + please any help would be aprecciated..

Your car is definitely 6 volt positive ground. I suspect the culprit is poor connections or cables. If the contacts or cables loose a small amount of voltage at each point, it doesn't take too long before the voltage the starter sees is below 4.5 volts. You should clean all the contacts and replace the battery cables if necessary with the largest diameter six volt cables you can find. Do not use the smaller 12 volt cables. Once this is done, I'm confident your starting problems with disappear.

Frnak

oh ok ill try that the cables are the originals so they are nasty looking,where can i find those 6 volt cables hardware store,home depo,pep boys,also my 6 volt stater solenoid went bad n i knt seem to find one can i put a regular 12 volt or no,so whats a positive ground n whats the differences with a normal negative grond thank you frank.

If the cables are as nasty as you say, that is most likely the problem. If you go to a good auto parts store (not the chains) and ask, you most likely will find the part you need. They may have to order it, but stuff for the 50's cars is still available. Try NAPA. Here in my area we have CarQuest groups and they have always been able to get the older stuff for me. Some after market regulators will run either + or - ground, but some will not. Try to use the correct replacement parts and you will avoid most of the problems your are having.

Frank

K FRANK ILL DO THAT BUT KN I PUT A 12 VOLT SOLENOID OR NO ALSO I WANT TO RE WIRE THE INSIDE WIRING I GOT SOME 12 GAUGE HIGH HEAT RESISTANT INSULATED WIRES THAT LOOK LIKE THE ORIGINALS CAN I USE THEM OR NO DO I NEED SOME SPECIAL WIRES THANK YOU.DO U KNOW HOW TO POST UP PICTS.

While I have not tried using 12V solenoids with 6V batteries, I don't think it will work. There won't be enough voltage to activate the coil in the solenoid. I don't know what your high heat resistant wire is, but the correct wire should be available at stores in your area. I guess I don't understand why you can't use the correct parts.

Frank

if you can't find the cables try the cables from a 3 phase arc welder they are about the right size, also i would run another cable from the block to the frame

It doesn't make a difference if you're positive or negative ground except for the voltage regulator and possibly some of the gauges.

Since your car was positive ground from the factory leave it that way. Replace the battery cables. Positive side of the battery, flat braided cable, to the engine block. Fat round insulated cable to the atarter solenoid. And since you have started and run it with negative ground you need to polarize your voltage regulator immediately after connecting the new battery cables. The voltage regulator has three terminals marked F, A and B or BAT. The F terminal should be wired to the F terminal of the generator and the A terminal wired to the A terminal of the generator. The B terminal should be wired to the same post of the starter solenoid as the battery cable. Take a short piece of wire and jump or short the B and A terminals of the voltage regulator. This will polarize the regulator to positive ground like the battery. It is also a good idea to run a ground cable from the engine block or from the battery ground post to the car body. Be sure there is bare metal where you connect the ground to the car body. Poor ground is a big cause of problems in 6 volt systems.

Bob is right, if your car came with positive ground, keep it that way for the sake of your gauges. If you have any motors with permanent magnets, they will run backwards if you switch polarity.

Replace your battery cables with 1/0AWG THHN or MTW stranded copper wire. Make two ground wires from your battery: Tie one ground wire as close to your starter as you can, but still on the engine block. Run a separate ground from your battery to the sheet metal chassis; #8AWG THHN or MTW stranded copper wire. If you can't find the wire at Home Depot or Lowe's, or if you want the very best wire, ask your electrical contractor's supply store if they carry 1/0-welding cable. It has at least a hundred strands (instead of 19) and is very flexible. The other battery lead (negative, in your case) goes to the heavy starter relay post, then continues from the other large relay post to the starter.

All these connections MUST BE TIGHT. Crimped connectors work best, not soldered connections. Clamped connectors are ok, too. Loose or rusty connections won't work.

Keeping your battery fully charged is important. If you don't run your car much, put the battery on a float charger.

THANKS GUYS FOR ALL THE VERY IMPORTANT INFO I REALLY APRECIATE IT I WILL START BY GION N GET THOSE WIRES N REPLACED THEM THE WIRE I WAS TALKIN A BOUT IS A 12 GAUGE INSULATED WIRES THEY USE THEM FOR THE KITCHEN EQUIPMENT LIKE STOVES N THEY HOLD ALOT OF HEAT I BEEN TRYIN TO POST A PICT BUT I KNT SEEM TO DO IT, ILL KEEP U GUYS POSTED ON MORE WORK, DOES ANY ONE WHERE TO GET THE OLD MARBLE LOOKIN TYPE OF KNOBS 4 LIKE THE LIGHTS HEATER SHIFT KNOBS ETC, ALSO WHERE TO GET THE STUFF THAT U CAN PUT ON THE LICENSE PLATES LIKE FLAG HOLDERS THE SHERIFF TYPE STAR N LITTLE NICK NACKS LIKE THAT THANK YOU AGAIN.

Kitchen equipment STARTS at #8AWG copper, and goes up from there. 12-gauge copper wire is only good for 20-amps; FAR TOO SMALL for a starter of any kind.

O ok thank you cause my wire was a 12 gauge and I was thinking to use them for the inside wiring and some of the engine like from the regulator to the inside wiring. So what kind of wiring should I ask for when I go to the Electrical outlet store and what gouage should it be? I see there is 2 types of gauges but im not sure what they are!Also I cant find that braided wire that goes from the negative of the battery to the block or the block to the chasis. Thanks Again for all your help

Let's start from your 6-volt battery.

Get 1/0AWG (American Wire Gauge) copper stranded wire. If you can find 1/0 WELDING WIRE, get that at the electrical contractor's store or lighting gallery. If you can't find welding wire, use THHN (they sell it at Home Depot). You need enough to positive-ground your block. In addition, use a #8AWG copper stranded THHN, to positive-ground the body from your battery.

On the battery negative side, get one length of 1/0AWG to your starter relay, then another from the relay to your starter motor. Use crimp-on (not solder) ring terminals (lugs) on the relay and starter motor. These terminals are big enough to slip 1/0 wire in, and crimp tight. Make sure the terminals have holes large enough for the studs and nuts.

From the Generator to your Regulator (the big wire), use #10AWG copper stranded wire. THHN type wire will do, but MTW type has a softer vinyl coating with less 'memory'. (MTW will stay where you put it.) The generator Field wire can be much smaller, like #14AWG stranded copper THHN.

You can use #12 for inside branch wires, but it should be fused for 20amps.
#14 is fused at 15amps
#10 is is fused at 30amps
That should get you goin'

THANK YOU SIMPLE CONNECTED ILL RUN TO THE STORE TDAY OR TOMOROW ILL KEEP U PSTED.i was thinkin of switchen to 12 volts but i just wanted to run a cd player in it with 2 6x9s speakers n 2 4inch on the doors so i dont think its worth the trouble to convert but i do need to re do my wire harness but damn there xpensive u think i kn make my own. by just re tracin my old ones there all there.

so i went to the electrical store outlet n they dont carry that type of wires they said that they dont carry that type of wires that i need to go to an auto parts store but i did try a couple of them n they dont carry it neither so my next stop is home depo n lowes hopefully theyll have it but do u have any more places thank you.

Where do you live? Have you got a store that sells welders? If not, then you will have to buy THHN wire at Home Depot or Lowe's. THHN is stiffer, but it will work ok. If they don't have 1/0, then get 2/0.

i live n tucson arizona ill try a weldin place tomorrow n ill keep u posted k thank you.