educate me on 6 volt systems

[resq302]

Well, being that I have never worked on a 6 volt system car before I helped my friend get his 55 Ford Fairlane running, I realized that I need to learn a lot about 6 volt systems in the future for helping him get is car road worthy.  Anyway, fortunately he had his battery charger (6 volt) on the battery the whole time so we didn't need to jump it to get the engine running but it got me thinking..... how would one jump start a 6 volt car when all newer cars are 12 volts and the booster packs are also 12 volts.

He is considering getting a 12 volt conversion kit as he is not worried about originality with the car but then that brings up other issues with the entire electrical system diagnostic should there be a problem with any wiring or spark coil, etc, in the future.

Any insight would be appreciated to help me gain more knowledge on this.

[Todd Wilson]

This is a clip from the Dodge truck guys..............

Todd

=================


There is only one correct way.

Before you connect any jumper cables, check the 6v polarity since many 6v systems were positive ground and you have to match the batteries, not the vehicles. Also, you must be sure there is no metal-to-metal contact of the two vehicles.

Next, you need a second person. If you hook up the jumper cables from a 12v to a 6v vehicle and then go get in to start it, you will blow most of the 6v circuits. That's why there are no working fuel gauges on the 6v trucks.

Turn off every thing on the 6v vehicle.

Have the second person connect both cables to the 6v battery being sure to observe polarity.

Have the second person connect the 6v positive cable to the positive post of the 12v vehicle. Do not connect the negative cable to the 12v yet.

The driver of the 6v vehicle turns on the ignition. As the driver hits the starter switch, the second person TOUCHES (does not clamp) the remaining negative jumper cable clamp to the negative post of the 12v battery. This is only done while the 6v starter is drawing a full load. If the driver (6v) releases the starter switch, the second person immediately removes the negative cable clamp from the 12v battery.

There is no problem with the 6v starter operating on 12v. Many vehicles are using 6v starters on 12v systems.  The problem is that you might "fry" the 6v generator, voltage regulator, 6v battery, and any other instruments or accessories on the 6v vehicle with 12v.

The 6v starter motor "absorbs" the additional voltage so it does not harm any other 6v circuits, BUT ONLY WHILE IT IS CRANKING THE MOTOR.

I repeat this important instruction. Make contact with the 12v battery ONLY WHILE THE 6v STARTER IS DRAWING FULL LOAD. Break contact with the 12v battery instantly if the driver releases the starter switch, either because he quits cranking or because the 6v motor starts.

There is always a risk of a battery explosion. I'm not an engineer but I expect the 6v battery is more likely to explode. I've had 12v batteries explode and it was always the one getting the jump. The second person should wear safety glasses and protective clothing. Safety First!

I grew up with 6v, positive ground vehicles. I learned to do this correctly and never hurt a 6v system. I will consider converting each of my 6v vehicles to 12v in case I have to jump one of them when I am by myself. This may be the most practical reason of all for converting to 12v.

Of course, being able to add certain 12v accessories - radios, tape and CD players, spot lights, driving lights, etc. - can be another reason for having a 12v electrical system. 

[Todd Wilson]

Clip from the Dodge truck guys................


Todd


===========================

POLARIZING THE ELECTRICAL SYSTEM

Whenever a generator or a generator regulator is tested, repaired, or replaced, the generator must be polarized.  If this is not done, the generator may be damaged and the regulator contacts burned.  Reversed polarity will discharge the battery - or damage it. 

There are two types of generator and electromechanical voltage regulator combinations used with DC generators. 

In an "A Circuit" system, the field is grounded through the regulator.  "A Circuit" systems are found in most Ford and GM vehicles. 

Most Chrysler vehicles had a "B Circuit" system which was grounded internally through the generator. 

To polarize an "A Circuit" system, connect the FIELD, ARMATURE, and BATTERY leads to the regulator.  Connect the battery.  Then, momentarily connect a jumper wire between the ARMATURE terminal and the BATTERY terminal at the regulator.

To polarize a "B Circuit" system, connect the FIELD, and ARMATURE leads to the regulator.  Connect the battery.  Then, just before installing the BATTERY lead, momentarily touch it to the ARMATURE lead terminal. 

VC and WC 1/2 ton military 4x4 Dodge trucks without radio set ups had 6 volt electrical systems with the POSITIVE battery terminal grounded.

WC 1/2 ton military 4x4 Dodge trucks with radio set ups had 12 volt electrical systems with the NEGATIVE battery terminal grounded.

The following 3/4 ton  4x4 Dodge trucks had 6 volt electrical systems:  WC-51; WC-52; WC-54, WC-59; and WC-60, as did the 1 1/2 ton 6x6 WC-62 and WC-63. 

The following 3/4 ton  4x4 Dodge trucks had 12 volt electrical systems:  WC-53; WC-56; and WC-57. 

All 3/4 ton 4x4 Dodge trucks and 1 1/2 ton WC models had the NEGATIVE battery post grounded

While the voltage was different - 6 volt vs. 12 volt, the steps to polarize the generator are the same.

The old generator with an electro-mechanical regulator is a rugged, versatile set up.

We can convert a POSITIVE Ground system to NEGATIVE Ground by changing the polarity of the battery and the generator; and switching the leads on the ammeter to show a charge when it's charging.

We can also increase the output voltage of a 6 volt generator and use an 8 volt battery by adjusting the voltage regulator. I know of folks who increased the voltage a bit more and use a 12 volt radio with an 8 volt system.

SOURCES:

Automotive Electrical Systems, Classroom Manual and Shop Manual, Harper and Row Publishers

TM 10-1123/1443, Maintenance Manual, 1/2 Ton 4x4 Chassis, Dodge Trucks built for United States Army, Portrayal Press

TM 9-808, 3/4 Ton 4x4 Truck (Dodge), War Department

TM 9-810, 1 1/2 Ton 6x6 Truck (Dodge T-233, Models WC-62 and WC-63), War Department

[Todd Wilson]

I personally wouldnt convert it if everything is working on it now.  If the car has to have a complete rewire then its a consideration.    My old 47 Dodge is 6 volt and it does just fine with its system.   The headlights I find to be just as bright as my Chargers headlights.    They are no where near modern halogen types but they do fine for what they are.

Things I have noticed and read over the years are 6 volt systems tend to be less forgiving then a 12volt system. Stuff has to be right on the system and all will work well. I have heard guys putting an 8 volt battery in to help out stuff but its not needed and can sometimes cause problems.  All your gauges and light bulbs are 6 volt and anything other then 6 volt will burn things out. I had a friend convert his 54 Chevy truck to 12 and it was a major mess. Some of his gauges never did work again.


If his system is working fine on the car leave it alone.  Accept it for what it is and go from there. So many times people think they need to take an old vehicle and make it modern instead of enjoying it for what it is.


Todd

[resq302]

Thanks for the input Todd.  He is just starting to get into the old car hobby and is just learning which is why he called me over to help him get the engine running again!    I emailed him this thread so hopefully he can get more insight to the 6 volt systems as I am.  I just wish I had more time to be able to get up there and get more accomplished on the car.  The car is in phenominal condition considering it has only had one repaint and the interior is in fantastic shape and is all original!  Lets face it, how often do you find a car with 73,000 miles that is 57 years old and still retains its original interior and is a 4 door to boot!  Not that many people have saved 4 doors from the scrapper.  The floors on the car appear to be all original sheet metal as well as the trunk floor.  Looks like only the bottom part of the rear quarter panel was replaced at some point which is typical to rust out on any car. 

[Ghoste]

We deal with 6 volt systems all the time at auctions and around the restoration shop and we do it exactly how Todd described above.  The other thing we watch is not to let it crank too long and allow for a sufficient cooling time if you have to try it a couple of times.  You are hitting that starter motor with more than it was intended to deal with.

[resq302]

Well, here is the debate now we are having with me and the owner.  With having all the original wiring in the car, the insulation is drying out, cracking and falling off which is exposing all the wires.  Granted, it will cost a ton to rewire the entire car and change everything over to accept 12 volts but now might be the time to do it if he has to replace all of the wiring.  We are still weighing his options but I know he only wants to do this once and with part availability being what it is, he might be better off just converting it to the 12 volt system now than trying to find parts on a moment notice for a 6 volt system.

[Cooter]

Rewire that thing before you burn it too the ground. 6 volt systems were "ok" back in the 40's, but today, ever try to start one in the cold? SUCKS!
Parts are hard to come by if you break down on the side of the road. Not like your gonna run into auto parts store and just grab a brand new 6 volt Generaor off the shelf.

Re wire it, and update the charging/starting system. The car will thank you. There's even a little resistor thingy that you can wire into the back of the gauge Cluster to keep the 6 volt gauges.

[Ghoste]

Cooters right, if you want a reliable driver change it over now.  If you want a correct part investment, then go ahead and leave it 6 volt but based on what you are saying about the wiring, he will need to spend money on it anyway. 

[Todd Wilson]

That 6 volt starting in the cold isnt a problem. My old 47 Dodge starts in all kinds of weather.


Todd

[resq302]

Cooter, trust me, I did make him aware of the wiring issue since the wires for the blower motor had ZERO insulation left on it.  I just know he wants to get it on the road but at the same time, the cost of the conversion might be a big issue.  He had me look over the car and make up a list of what needed to be done to get the car roadworthy.  Replacing the wiring inside the engine compartment was a biggy due to the insulation missing and such.  Over all the car is a very good and solid car which is always a plus to start with.  All of the trim is there and in excellent shape with the exception of some of the white metal chromed stuff.

I told him when I did my car, I picked one area to do per year as not not over burden myself with costs.  The main thing is that we got the engine running although it smokes a bit from the driver side, it has gotten better the more it ran probably due to it sitting for so long.  Oil was changed prior to attempting to fire up the engine and the oil that came out was fairly clean mainly from the lack of running it.

The next object to tackle is to make it road worthy.  Getting the engine tuned properly and then working on the electrical system so it wont burn!

[Cooter]

 I've seen too many burn to the ground to be in a hurry to leave some old, outdated, wiring that has no insulation. Not cool.

[resq302]

I've seen too many burn to the ground to be in a hurry to leave some old, outdated, wiring that has no insulation. Not cool.

Oh, I agree which it was the first thing that I pointed out to him when I was looking over the engine compartment trying to figure out why it wasn't running.  I guess being a vol. fireman I have a niche for these things and fire safety!   

[aussiemuscle]

I'd convert any 6 volt car i had to 12 volt, just for the convenience. Same as if i had a model T, i'd change the controls to the (Cadillac) Standard layout (accelerator = right foot, etc).

I have heard guys putting an 8 volt battery in to help out stuff but its not needed and can sometimes cause problems. 

That's because it needs more AMPS, not more volts. i use extra-heavy duty battery so it works all winter.

[FLG]

Brian,

After talking with you on the phone i think you said he had the battery hooked negative ground, im almost sure that car should be positive ground.

[myk]

Well, here is the debate now we are having with me and the owner.  With having all the original wiring in the car, the insulation is drying out, cracking and falling off which is exposing all the wires.  Granted, it will cost a ton to rewire the entire car and change everything over to accept 12 volts but now might be the time to do it if he has to replace all of the wiring.  We are still weighing his options but I know he only wants to do this once and with part availability being what it is, he might be better off just converting it to the 12 volt system now than trying to find parts on a moment notice for a 6 volt system.

How much is it going to cost to rewire the car?

[resq302]

Brian,

After talking with you on the phone i think you said he had the battery hooked negative ground, im almost sure that car should be positive ground.

Frank,

From what I remember even before I started tinkering with the engine to try and get it running, I recall seeing the - side of the battery having the cable go to the engine block so if that is the case then it would be a neg. ground.  Again, its hard to say what has been done over the 57 year life of the car.

Myk-

Its hard to say how much it will cost to rewire the car as my friend has all of the resto part books and such.  Either way, he is going to have to replace the wiring at some point since the insulation is cracked and even missing on large sections.  Also, I read that 6 volt wiring is a heavier gauge of wire than what 12 volt wiring would be.  To keep everything correct, the entire wiring should be replaced so as not to have too heavy of a wire which could cause problems at other places should a short occur.  Lets face it, whatever the cost of replacing wiring for an entire car and the components is probably cheaper than replacing an entire car should it short and catch fire.  Also,  updating the car to 12 volt system would allow for modern things to be used such as a cigarette lighter charger for our cell phones, newer/better radio, after market gauges, etc.

[FLG]

According to the web its positive ground, double check things and always wear eye protection when working with batteries.....even if just connecting a cable or jumping a car, i keep my head above the hood and if thats not possible and i dont have goggles ill line it up and close my eyes when attaching things, they explode for no dam reason sometimes.

[resq302]

Next time I go there, I'll probably try and take some pics of the car to post up on here.  Lets just say that when I was under the car, there was easily 57 years of grease build up!  But they sure don't make cars like that anymore either!

[FLG]

3 speed on the column? I always forget where every gear is.

We've been working on my uncles 42 Packard 180, that thing was ahead of its time.

[resq302]

nah its a grily-matic.   

[myk]

Myk-

Its hard to say how much it will cost to rewire the car as my friend has all of the resto part books and such.  Either way, he is going to have to replace the wiring at some point since the insulation is cracked and even missing on large sections.  Also, I read that 6 volt wiring is a heavier gauge of wire than what 12 volt wiring would be.  To keep everything correct, the entire wiring should be replaced so as not to have too heavy of a wire which could cause problems at other places should a short occur.  Lets face it, whatever the cost of replacing wiring for an entire car and the components is probably cheaper than replacing an entire car should it short and catch fire.  Also,  updating the car to 12 volt system would allow for modern things to be used such as a cigarette lighter charger for our cell phones, newer/better radio, after market gauges, etc.

Agreed on all counts.  Just trying to see what other people are paying for this sort of work as I'm getting ready to have the Charger completely rewired as well...

[resq302]

Myk,

Im sure it would cost you a lot less as the charger is already wired for a 12 volt system.  You have a LOT less things to replace.

[myk]

Myk,

Im sure it would cost you a lot less as the charger is already wired for a 12 volt system.  You have a LOT less things to replace.

Agreed.  Even with the possibility of having to replace a socket or two and some other odds and ends I was quoted about $1200 for parts and labor.  I'd do it myself but I want it done right the first time...