This has been brought on by my research into 6 volt electric fuel pumps:

Does anyone know about making a 12 volt "loop" in the system of a 6 volt battery to run 12 volt electrical stuff?

I have a 6 volt system, and I do not want to convert to 12 volts. However, I have a distant memory of Ohm's law or Kirchoff's law. It seems like it should almost be as simple as wiring a voltage resistor in series with a 12 volt component to make that part jump to 12 volts... BUT if it's that simple, I would have read about it right? But - but - but ... V=IR.. ?

Does anyone know what I'm talking about and if it will or won't work, why and how?

 

It's not that simple, you can drop voltage with a resistor but you can't jump it up. There are converters sold to bump 6 volt to 12 volt but you will cut the amperage by half, Ohm's law, and I'm not sure if the converters being sold are able to operate a fuel pump, they're mainly used for radios.

 

Actually you can make 12 volts out of 6 volts by connecting two 6 volt batterys correctly. Only thing though is you will have two ways of doing it.

Have a battery hidden in the cab and have that battery doubled to the main 6 volt battery in just the circuit you want to have 12 volts and keep the second battery isolated from the main electrical system but you still have to have a way for the generator/alternator to charge both batterys.

Another option is to link both batterys under the hood and then use resistors to drop the voltage down to 6 volts everywheres but where you want the 12 volt circuit but if you do this route be easier to just convert to 12 volt system.

 

There is such a thing as a voltage doubler and have seen them advertised somewhere but didn't seem very cost effective as it can depend on how many amps you need the thing to provide. Probably cheaper and less hassle to get the correct voltage fuel pump.

 

If you can do that - and make it run a fuel pump - you'll be a rich man.

Just be careful when you try - you could let the smoke out of the wires.

 

I was wondering about that 2 battery idea, wrestling with wiring a small one in parallel to charge, but in series for other reasons but I don't see that working without some fancy stuff. Maybe it could charge directly from the generator.

Bobj talking about the converter lead me to look up that stuff and I found a couple ("Step-up transformers" or "voltage boosters" or "6 to 12 inverters" etc.) that seem to be rated for 5 amps continous. I thinks that is enough for the fuel pumps I saw, but I still confuse it by wondering if that is the amps in the converter or out... Either way, they all seem to be $50 to $100 bucks so Gearhead1952 hit the nail on the head as far as common sense.

haha I'll try to keep the smoke in the wires! Rich man you say? I doubt it - at this point I guess I'll figure out if I can make a transformer with magnet wire and shape while I order a 6v pump.

 

have you considered using an 8 volt battery? the generator will still charge the battery and you headlights will be some brighter.also it may run a fuel pump.

 

Help me Lord!

Why Why Why do you guys continue to try to do garbage like this? It seems like some Witch Doctor has put out some "quick and dirty " electrical advice that would make a perfect classroom cirriculum at the College for the Certification of Previous Owners

NO!!!!! there is no satisfactory device at the automotive level to increase voltage and polarity from 6 volt positive ground to 12 volt negative ground except for very small application resistance/inverters for radios. Even if you hook the two 6 volt batteries together in series and draw on one a mid point, or God forbid you try and blow yourself up by drilling a hole in a 12 volt battery to obtain 6 volts, you still have the polarity/ground issue. Not to mention the wire gauge problems (like fire) you have running a dual voltage truck. These electrical systems are very fundamental. Incorporating these types of "improvements" turns them into an electrical nightmare.

If you want to run an electric fuel pump on a 6 volt system buy a 6 volt fuel pump for crying out loud!

If you can't live without an electric fuel pump and 12 volt is all you can find, your going to have to convert to 12 volt negative ground and use voltage "reducers" to power your 6 volt components if you can't find 12 volt replacements.

And I warn you...if you write back and tell us you are doing this because the 12 volt pump was only $5 off a 91 Crown Victoria or some such hooey, and a 6 volt pump is almost $30, I swear on my grandmothers grave I will hunt you down and slap you silly.

Love you!

 

lol, no, if you type "6 volt fuel pump" into google you will find references to Bendix 6 volt pumps etc. It looks like Bendix was taken over by Facet, who makes a pump that looks identical to my old Bendix which I want to replace, but it is 12 volts. So, when I learned Facet doesn't make 6 volt stuff anymore I decided that with a 6 volt system, and all of the 6 volt products disappearing, someone should know how to hack a loop (Wrong thinking = 25 cent radioshack fix: V=IR double resistance to double voltage: 2V=I(2R)?? No, I guess not.) Now I guess Step up and step down transformers are for AC, so, like they said, a converter would work, but it costs more than the pump and for now, it isn't needed - just buy a 6 volt pump. If I really want to learn how to make a 12 volt loop in a 6 volt system one of those converters could be opened and learned from I guess.

(Drill a whole in a 12 volt battery? Hmmmm. Well, how about two holes in the middle and posts to make two six volts?) No slapping silly, that might generate worse posts.

8 Volts is too expensive to try. But I guess that means the generators charge at that voltage.

Off subject: does anyone know why the positive ground was given up for the negative ground? was it lightning? That's all I can think of because the earth is positive.

 

Also, JC Whitney stopped selling 6 volt pmps

 

way I understand it a negative ground produces no sparks when you remove the ground. Postive ground produces a spark when you put the cables on. Same with postive breaker points (not just the dist breaker points im including contact points) they spark and arc. Some import car uses negative side to put the contact points in and they dont spark or arc out and they dont wear out as quickly. I think that is why they went to that. But that is just what I think I might be wrong on that.

 

It doesn't matter what polarity your setup is its gonna arc no matter what. This is why when your boosting a vehicle that the ground goes to the frame than the battery on the one side cause if your battery just so happens to be not fully sealed, the spark can ignite the hydrogen gas.

Theoretically with a positive ground system you could shock yourself if you were grounded and touched the body of the vehicle. Not that I would recommend you holding onto a ground rod and grabbing your vehicle...

 

Electrician told me that grounding rods for lightning rods bring the positive charge from the dirt up to the wires to attract the lightning instead of the house. So, I thought positive ground would be better for battery life... Is the terminology different

 

6 volt electric fuel pumps are still readily available. I have asked about them at my local Napa, and they have listings. Same with CarQuest, Schucks, etc., etc. Most of our restoration suppliers also list 6-volt electric fuel pumps. They are on average, $30-$60 depending on who, how, where, and why. People are putting too much stock into just googling things. If it were that easy, we'd all be rich. I think I may still have a 6 volt electric fuel pump, I'll check tomorrow. What's wrong with going back to a mechanical? Originally, your vehicle had one, and they are all still available for all the old Ford truck engines. I don't buy the touching the car body and getting shocked story just because it's positive ground. Heck, I've touched bare metal on new cars and gotten a zing, and they're all negative ground. It doesn't matter what the polarity is, if you complete the electrical circuit, you're gonna get a zing. Does it happen more on positive ground, I don't know, I've never noticed a difference, but then again, I wear rubber soled boots, all the time.

 

I do agree with Julie though. Yeah boosters are available, but for small amp items, it really aint worth buring your rig down over a fuel pump.