start on 12v run on 6v

[nohelp]

Just wanting to know if you can rig up a system on a 50 6 voit car to start on 12 voit then run on 6? I tried search engine no luck there. thanks in advance for any help on this. NO HELP

[Ken/Alabama]

I'm sure it could be done but I must ask why???

[rotorwrench]

Carrying an extra battery around isn't all that practical. The start system would have to be isolated as just start and ignition so that that the two system voltages wouldn't be on line at the same time otherwise the higher voltage could do damage to some of the 6-volt components.

When everything is in good condition with proper gauge conductor cables the the 6-volt system works very well.

[drolston]

That is theoretically possible but quite problematic. If you are going to run on 6v, that means you have a 6v generator; how would you charge the 12v battery? How do you isolate the 6v components from 12v while starting? Failure to isolate could burn out bulbs, instruments, radio components, etc. As you can see this idea is way more complicated and expensive than simply converting the whole car to 12v, which has been done thousands of times by people with little or no electrical system knowledge.

[mfirth]

A well maintained 6 v system with proper gauge cables should start & run fine. Mine does.
Remember, in the fifties we drove cross country with 6 v systems. Make sure your grounds are clean & tight. Enjoy that 50 !! mike

[cederholm]

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I think you would be asking for trouble. Pick one and stick with it.

~ Carl

[19Fordy]

I recall folks used to tap 6V off the 12V battery. Back in 1963 I have a 40 with a 265 V8 installed and that's the way it was.

[cmbrucew]

It can be done with two six volt batteries.
Bruce

[petehoovie]

Is this a permanent system you're asking for or a temporary lash up?

[fortyfords]

I had a 12 volt battery in my 54 Ford for starting and the rest of the car was 6 volts, worked good but once in awhile I would have to charge the 12 volt battery. I would just fix the problems with the 6 volt system and eliminate the 12 volt battery. The only reason to have a 12 battery is if you have a hard starting engine because the engine needs fixed or rebuilt.

[bobH]

Originally Posted by fortyfords

I had a 12 volt battery in my 54 Ford for starting and the rest of the car was 6 volts, worked good but once in awhile I would have to charge the 12 volt battery. I would just fix the problems with the 6 volt system and eliminate the 12 volt battery. The only reason to have a 12 battery is if you have a hard starting engine because the engine needs fixed or rebuilt.

Look in Rumbleseats writeup. I have used his system in my own 47, for several years. Works good for me. As alluded to above, it's a total-loss system. I used a small (80 Fairmont) battery. The rest of the car only sees 6V, and only the starter sees 12V when you hit the starter.
Rumbleseat's 34 was a different story. It had a 'built', bigger flathead, with higher compression.
As mentioned above, my 47 was old and tired. The 6V system was in excellent shape, but there was that occasional time when it took 12 to make it go. I used it mostly as 'insurance'.

[1931 flamingo]

What once was old is new again...........................


I remember reading about this ages ago.
Paul in CT

[JSeery]

There is a relay setup to do this, it was sold primarily for use on VWs in the 60s. There was a thread on it I contributed to several years ago on the HAMB.

[fjz]

In the 50's I replaced my flathead with an Olds Rocket 98. 6 volts had trouble turning it over. I added a second 6 volt which I connected between the solenoid and the starter. Every week or so I had to relocate the batteries as only one was being charged. I came up with a system using a solenoid and as I recall a single pole double throw switch where with a flip I could change the second battery from being in series to parallel with the first. I doubt I could design it again.

[JSeery]

As I recall that is the way the solenoid worked, it switched the batteries (two 6v batteries) between series and parallel.

Found some current info: 6 Volt Series Parallel Switch Relay 6 Volt DC To 12 volt DC 1500 amp Series Parallel Switch Used on Older Cars & Equipment Start On 12 Volts & Keep Your Original 6 Volt Charging System.

http://www.texasindustrialelectric.c...1119845_6V.asp

[JSeery]

This is the one I was familiar with. Ran one in a 6v VW in Okinawa in the late 60s, LOL.

[Tinker]

Originally Posted by JSeery

As I recall that is the way the solenoid worked, it switched the batteries (two 6v batteries) between series and parallel.

Found some current info: 6 Volt Series Parallel Switch Relay 6 Volt DC To 12 volt DC 1500 amp Series Parallel Switch Used on Older Cars & Equipment Start On 12 Volts & Keep Your Original 6 Volt Charging System.

http://www.texasindustrialelectric.c...1119845_6V.asp

What would better would be if you can use a 12v battery on a 6v system

[JSeery]

It is not using 12v on the electrical system, that is the idea of the solenoid. The 12v connection is to the starter only, the solenoid is required to keep everything separate and to charge both of the 6v batteries. So, the vehicle remains 6v running on both batteries in parallel and the starter sees 12v from both batteries in series.

[J Franklin]

It would be cheaper and easier to just fix the problem than adding more to go wrong.

[JSeery]

Originally Posted by J Franklin

It would be cheaper and easier to just fix the problem than adding more to go wrong.

LOL, not in the situation I was in!!! Right at 100% humidity 24/7 for months. Had to remove the distributor cap every morning and wipe it out and then roll it down a steep hill to get it to fire. The solenoid setup worked well and solved the issue. I'm not a salesman for them nor am I promoting them, just answering a question. Obviously if they were that popular there would be more information on them around. I think they have a very limited application.