Anyone ever run a 6-volt system AND 12-volt system at once?

[Machinos]

Well, not exactly a whole 12-volt "system", just an alternator and a battery...

My car's already got an alternator mount on it, even though I'm using the stock 6-volt generator and everything else. 12-volt of course offers numerous advantages, but what I'm mainly concerned with right now is 1) a stereo and 2) better starting.

I miss my tunes, to say the least, and a portable CD player with headphones is a really crappy (and kind of unsafe) arrangement. Second thing is that it's only gotten down to 40 degrees here so far, but the nearly-new 6-volt battery was noticeably sluggish that morning and the car doesn't like to start that easily either. I'm still trying to decide if I should get an Optima battery so I can actually get to work this winter. But if I had a 12-volt battery in there, wouldn't it be possible to just run cables directly from it to the starter and get twice the cranking power, and additional juice? I could literally jumpstart my own car.

Main thing that concerns me is the voltage regulator. I know some alternators have internal voltage regulators, but I know that my '78 truck had an electronic voltage regulator on the firewall. I've got a 105-amp alternator already from my dad's old Subaru, but he had no idea if it had an external regulator or not. I also have no clue what sort of junction I would need to go from the alternator to the stereo and to the battery/battery cables.

Can anyone give me some advice on the matter?

[Jkustom]

well, I went to 12 volts in my 54 chev, and left a few 6 volt bulbs in, turnsignals ya see... and they were bright as fuck for a few minutes... my question is, why dont you just find an alternator that know know the story on, and do a full convertion? Or be like me and get a 12 v generator, and 12v regulator, and coil, and ballast resistor and.....To quote Hunter S. Thompson, "why not? anything worth doing is worth doing right!" -J.

[Missing Link]

I have seen this done before. It entails running two seperate batteries, one 6volt and one 12volt with a switch between them that will show the starter 1volts when you want it to. As far as a stereo is concerned, forget it with the 6volt generator. I finally got pissed off enough at my old 6volt system I converted to 12volt and haven't looked back since. It works much better with an alternator and 12volt battery, imo. That flatty starter spins like a mo-fo on 12 volts! http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif Regardless, the system would still be 6volts during operation and 12volts only at the time of starting the car.

[Machinos]

All those "and and ands" http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif I'll most likely do the conversion next year with a totally new wiring harness. The original one is pretty worn out and I don't want to mess with it more than I need to right now or I'll probably screw something up (moreso).

[Machinos]

[ QUOTE ]
I have seen this done before. It entails running two seperate batteries, one 6volt and one 12volt with a switch between them that will show the starter 1volts when you want it to. As far as a stereo is concerned, forget it with the 6volt generator.

[/ QUOTE ]

Yeah, that's what I'm saying...one generator, one alternator, one 6v battery, one 12v battery. The 12v would only run the starter and the stereo.

[Elrod]

they make a battery that has 12V cranking power, but once the car starts it's 6 volts.

I haven't heard you say why you want to keep the 6V side. Sounds like everything you want requires 12V.

Change out the battery. Get a 1 wire alternator. That does away with your regulator all together. Put a ballast resister on the coil and another resister on your gas gauge. Change out your light bulbs and drive.

12V has less amps than 6 Volts, so you don't have to beef up your wiring to handle it. 12V doesn't require as big of wires as 6V.


OH! What size are your battery cables now? Did you pick them up at the auto parts store? 6 V requires 2 gauge or 0 gauge to properly start the car. It's hard to find fat enough battery cables for starting 6V cars at the Autozone. That may help some of your starting issues.

[48_HEMI]

Desoto's 34 with the 70's CRAPHICS has dual systems, but I think he just did it because he's an electronic whiz. I can't see any reason you'd want to.
I used to run a "VOLT-A-DROP" on my six volt radio it gets hot so mount it somewhere safe http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[36-3window]

if you really want a dual system,with both 12 volt and 6 volt accesories...why don't you mount a 12 volt alternator and use two 6 volt batteries wired in series. that way the two together will give you the 12 volts,and anything you want to run off from 6 volts,just tap off one of the batteries. i've seen this done before. MG's before 1968(i think) used two 6 volt batteries in series

the advice on the heavy 0 or 2 cable is right on....the 4 gauge stuff you buy at the "auto parts" stores like checker,autozone,etc isn't worth using...even on a 12V system

[=mike=]

It sounds like ALOT MORE TROUBLE to try to have to seperate charging systems , than it would be do just wasp over to 12v unless you already have an excelent working condition 6v system ( almost an oxymoron ) I would just go 12v and get it over with .

[Paul2748]

Go with the full 12v system. 6 volts is old technology. You will be really happy you did. You can get your generator converted to 12 volts if you want to keep that. Starter does not have to be converted.

[Machinos]

Well, the main thing is the ballast resistors for all the 6-volt stuff that I need to keep, mainly the gauges and the stock radio (I still want it to work!). Replacing the coil and all the bulbs would actually be the cheaper part from what I've heard.

[Elrod]

For some big bank, you can have that radio retrofitted with FM, CD player inputs, and switched over to 12V. I think it's $300-$500. That is if you have to have the dash radio work. Otherwise, just put some light bulbs behind the face and hide a modern stereo in the glove box.


Check out this website:
http://www.antiqueautomobileradio.com/

[36-3window]

[ QUOTE ]
Well, the main thing is the ballast resistors for all the 6-volt stuff that I need to keep, mainly the gauges and the stock radio (I still want it to work!). Replacing the coil and all the bulbs would actually be the cheaper part from what I've heard.

[/ QUOTE ]

yeah,converting the whole system to 12 volts is best.voltage drops for the gauges are available from Speedway for $17.95 each...not cheap...and you will need one for the fuel,water temp,oil pressue gauges. the amp gauge doesn't need one. these are referred to as "runtz" type,they are transistorized and rated for only 1 amp.so you can't use it on the radio. you may have to learn to sing!

[Machinos]

yep, that's the problem, I can't really afford all that stuff right now. If I had both systems at once, though, all I'd need to buy are the necessary wires/cables.

[cadlights]

Here's a temp fix. Buy a 9 volt battery, it spins the old flathead like a 12 would. If ya drive it a lot bump the regulator output to 10 volts. It tends to wear generator
brushes faster, or ya can put a tickle charger on it every night for an hour to keep it topped off, That's what I do.
Put a 12 volt in the trunk and run wires to a radio under the dash or wherever and trickle charge it for an hour a night. I have mine hooked up to a timer. Works great.
No need to change bulbs or put anything on the gauges.
When ya get time and money do the changover.

[four-thirteen]

It's easy to run the two systems. Just attach the alt and battery normaly, grounded as normal. Run your 12v wires to the stero, and use another relay for the starter, so the 6 volts normally routed to the starter goes to the relay, which provides the 12v direct. I read about someone doing this recently, I think it was in one of my old car crafts or hot rods from the 60s.

A complete 12v conversion would cost alot, i think. New bulbs, gauges, reconfigure the engine wiring. easier just to start over and do it from scratch. I'd do the 6v+12v system before I did that. You still want that motor? Dave

[Machinos]

Actually, I dunno how to attach the alt and battery "normally" http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif On my two old cars there's a big junction box of some kind mounted on the fender, and on my truck it all just went behind the engine to the firewall and became a mess of wires I couldn't make any sense of. What kind of thing do I need to buy to split up the alt and starter and stereo?

I'll pass on the engine, I decided I've got too much junk already http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif I still have access to my truck, and since my job is only about 2 days a week right now, I could probably deliver it to anyone who's interested in it for less than it'd cost to have it shipped.

[Missing Link]

[ QUOTE ]
Buy a 9 volt battery, it spins the old flathead like a 12 would. If ya drive it a lot bump the regulator output to 10 volts.

[/ QUOTE ]

This was an old upgrade from the 6volt system that was done in the early to mid 50's. It was an improvement to the 6volt system prior to the introduction of standard 12volt systems. That is how my ford was done, but it hardly spun the starter like the 12volt system does...9volt to 12volt at the starter isn't even close imo.
FWIW, to completely upgrade the system in your vehicle, expect around $300-$400 depending on the wiring harness you buy. Now that amount of money would cover all new components; every switch, relay, bulb, voltage reducer, ect. Not very cheap but a good investment I think. It is a much safer system and easier to trouble shoot.
My car was in excellent condition when I purchased it, but the wiring was absolutely horrible. I think 50 or 60 year old wiring isn't safe, efficient or reliable and should be replaced. It's worth saving up the bread to do.

[four-thirteen]

To attach them normally, ground the negative side of the battery to the frame. The easy way to do it is use a one wire alternator, and run the wire to the positive side of the battery. Ground the groud wire on the stereo, like always, and attach the positive wire from it to the alt/battery positive terminal. Lastly, for the starter, run a big, heavy cable from the positive battery terminal, to one terminal on a ford type 6v starter relay. Run another cable from the other terminal on the relay to the starter and the starter solenoid. This will make it so when the ford relay is engaged, the starter will turn over. Just use the original wire from the 6v starter to engage the new relay.

It's really pretty easy. If you want help and are willing to drive down to my place, I'll help you with it. Dave

[desoto]

Yea, I’ve been running a 6 volt generator AND a 12 volt alternator on my hemi since the mid seventies. My sidevalve six powered ’48 Chrysler’s got a dual system, too.

Aside from the labor involved in mounting the extra charging device, it’s pretty easy to do. Just remember to switch the 6 volt system around to negative ground. Swap the wires on the ammeter so it doesn’t read backwards and you shouldn’t have to worry about anything else.

In my hemi-powered ’34 I run a FoMoCo style starter solenoid BETWEEN the two batteries so that, ONCE I ENGAGE THE STARTER ON 6 VOLTS, I hit the other “starter” button and that hooks the 12 volt battery to the 6 volt battery and I get, effectively, 8 volts across the starter. You DON’T want to jump the 6 volt batter with the 12 volt battery UNTIL the starter’s engaged and putting a load on the system.

Never burned out a starter, generator or alternator doing it that way and I’ve racked up over 210,000 miles on the car.

The ’48 starts fine on 6 volts and the 12-volt system’s just there to power the CB, Radar detector and pre-luber (engine lubrication priming pump). There’s no solenoid between the two batteries like there is on my ’34.

Why’d I go w/ the dual system in the ’34? Well, when I bought the car in ’64 the dome light bulb was one of the few things that was actually “in” the car…..AND IT WORKED. It worked right up until the spring of ’02 when I inadvertently hit it w/ 12 volts and burned it out. It’s still 6 volts, BTW.

Anyway, I left the generator in there ‘cause the dome light bulb had lasted for the 38 years I’d been driving the car and I still use a 6 volt starter…..and heater blower, electric fuel pump, dash lights and horn so it made sense to leave things alone. Besides, the ONLY 12 volt starter that would fit my flywheel was the ’56 unit. The 6 volt starters are the same from ’39 to ’55. (lots more to pick from in bone yards and swap meets)

I converted the running lights to 12 volts in ’86 but that was the extent of it. The CD Player, CB, Radar detector and cigar lighter are, now 12 volt units.

[Machinos]

210,000 miles? wow http://www.jalopyjournal.com/ubbthreads/images/graemlins/ooo.gif How many rebuilds is that?

[desoto]

Third block, second crank and rods, same heads, pistons, camshaft, starter, generator. I bore out a new block to fit my 1/8" overbore pistons and go from there. The second block was necessare when the engin sat for 18 months waiting for the courts to find the idiot that u-turned into me in '66 guilty for the last time. When I went to put it in the car, teh cylinders were all rust-pitted.

It's had a few valve jobs, though. Valve guides don't last long when you're running a high-lift cam.

[Digger_Dave]

Skip, it's been a long time! How are you keeping?

I'm trying to remember the engine and cam your running.