I need 12 Volt

[Guest]

1949 Chrysler Windsor 4d with fluid drive, I intend to make this car a survivor and be able to drive it at any given time and not worry about dings and bings. I would like to swap to 12 volt and keep my 6 volt gauges and radio, I would also want to swap from incandescent bulbs to LED'S and I am hoping some one can put me on to some type of step down from 12 to 6.

Thank you

[casper50]

Jimmy why do you need 12 volt?  6 does fine.  They even make 6 volt leds if you want them.  Much easier to just leave it 6.

[John Fleming]

I agree with first response . I drive a 1948 Plymouth with six volt with good performance .  Get a six volt optima battery and be on your way.

[Worden18]

6v here too on my 51.  No problems whatsoever.  My 67 year old halogen headlights outperform my newer cars without a doubt.

[DrDoctor]

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Edited May 16, 2018 by DrDoctor

[dpollo]

If 6 volts and 6 cylinders won't take you, you don't need to go.

[matt167]

you don't need it on a Mopar.. The 8v will work but you risk the radio.. I have a stock '50 Plymouth with an aftermarket Carter 6v fuel pump. Starts every time

[garbagestate 44]

The hard part about that job is the electric controls for the m-6 transmission. It's all 6 volt pos ground.I talked to a guy with a 49 who converted to 12v and he said he had no problems but who knows? If you damage any of those parts,they can be pricey and hard to find.

[busycoupe]

If you want to change to 12V because it is slow to start, perhaps you need to clean all of the battery and starter cable connections.  You may need new starter cables.  They should be quite thick, #1 or #0. The #2 cables used on 12V cars are too thin. You should also Che k to make sure there is a good ground connection from the block to the body.

[Adam H P15 D30]

Ahhh, don't let the nay-sayers get you down. A little work now to upgrade to 12v and a lot less headache down the road, but your radio will not work when changing polarity unless it is reworked to operate on neg. ground.  AMP gauge doesn't care how many volts go through it, a $15.00 RUNTZ resistor for the fuel gauge and you're good to go.  If you have a trans with solenoids, I ran an R10 overdrive solenoids for years on 12v with no issue.  If you drive it a lot and have to change a light bulb in the middle of a trip, 12v bulbs are everywhere!

 

Adam

[Worden18]

Just replaced my battery cables and starter to relay cable with #0; turns over about 50% faster than it did before; I can hardly believe it.  Been meaning to do this for about a year now and finally got around to it.  Between the Pertronix kit with the 40,000v coil, my new aluminum heat shield, and a few tips from some fellow forum members on starting the car when its hot, I'm in a good position.  Learn something new almost daily on this forum.  Who needs 12V?

[sser2]

12V makes sense. 12V alternator weights less, yields higher electric power, and, unlike generator, works efficiently at low rpm. It is more reliable and worry-free than generator+external voltage regulator. 12V allows transistorized ignition and electric radiator fan, among other things. Vibrator power supply in antique radio is such a bad thing that it should be replaced with a .modern DC-DC converter. Anyway, one cannot have a functional antique radio without at least some expertise in electronics.

[Don Coatney]

I have a P-15 with 12 volts negative ground and a D-24 with 6 volts positive ground. I am happy with both. Starter cranking speed is a bit higher on the 12 volt car. But with healthy engines in both cars starting is not a problem as far as the electrical system. I also have a 6 volt positive ground alternator in the D-24.

 

 

 

 

[jyinger]

I thought I would be the loan voice in support of the conversion to 12V, then I read Adam.  So I am not alone.  I have two 1942 DeSotos both still have 6V.  They work fine, as long as I keep the batteries fully charged.  No modern sound system though.  The third (!) 42 DeSoto, which is in the works as we speak, will get 12V.  I also have three 1952 Chrysler Imperials--two drivers in good mechanical condition, and a third one (convertible) in the midst of a frame-off restoration.  All have been converted to 12V.   Changing bulbs is easy, most of the gauges are easy to convert, clocks get rebuilt, and radios get replaced with modern 12V sound systems.  The 12V cars start so easily!  And the alternators keep the batteries fully charged, even when you drive the car for just short trips.

 

Go 12.

[casper50]

You can buy a 6 volt + ground altenator.  I have one on my coupe.

[matt167]

As far as 6v bulbs. My local auto parts store carries them in stock. Headlights are an order in item, but a next day item at that

[Adam H P15 D30]

The wiring harness is probably junk anyway....  Unless you are going to a full restoration why keep the antiquated 6v system?  You have to use a specialized wiring harness to handle the increased amperage and instead of one of the many 12v harnesses and FUSES that are manufactured for people doing what you are doing.  I did the 6v thing for a few years on my 49, but I like using it for the quick trip to the store, over to a buddy's house 1/2 mile away.  Using the heater and lights on short trips during winter nights and I got tired of plugging the damn trickle charger in all the time.  Some of that could be solved by a 6v alternator as Don and others pointed out but why?  You're changing the harness anyway...  Remember, the factory harness has no fuses and 1 circuit breaker for the headlamps.

As Worden 18 points out, transistorized ignition is available for 6v systems but Pertronics is a specialized component and if it fails out in Timbuktu, you will be waiting a few days for a replacement unless you carry a spare or spare points to revert back.  I am not a huge fan of these type of components on drivers, better to find off-the-shelf solutions for ignition systems and other mods that is readily available at NAPA or other stores.  Unfortunately that almost always requires the vehicle be up to "industry standard" hence 12v.  There is a reason the manufactures switched to 12v in the mid 50's.

 

This is one man's opinion and should be taken as such,

Adam

Edited May 16, 2018 by Adam H P15 D30

[kencombs]

I won't give an opinion.  But, I will say that my '56 PU is 12v from the factory, but now has an alternator replacing the generator.  Mother Mopar changed for a reason.

[dale]

I don't know how to do it but I had a 51 Plymouth that was converted to start on 12 volts but ran everything else on 6 volts.  You turned the key on and pushed the button on the dash for 12 volts with the key on.  It had two 6 volt batteries.

[dale]

13 hours ago, casper50 said:

You can buy a 6 volt + ground altenator.  I have one on my coupe.

Most of the starting problems with a 6 volt car is usually a half dead battery.  Put on a one wire altinater  sp.  and eliminate the voltage regulator and a ton of charging problems will go away.  IMO