12v battery in 6v system

I am in process of buying a car and the guy i am buying it from said "it wouldnt crank fast enough with a 6v battery" so he put a 12v battery in there and now he says if "cranks up much faster, like i think it should". I have never really had to deal with a 6v positive system before like the one on this 1937 plymouth. Can someone tell me if this will damage the car and screw me over later?

Thanks, Austin

 

You don't state whether or not he properly converted it. If he did, then you are O.K.

EXCEPT:

If it's a 6 volt car and it's needs a 12 volt battery to turn it over, there is something wrong with the car. ie: starter or something.

Converting simply because you want a modern radio or brighter lights are one thing. Converting simply because it won't start is another, IMO.

 

If he just stuck in a 12V batt without doing the other needed changes you may have a shot gas guage o/p and temp gauges if electric etc. 6 volt systems need at least O cables and a batt with enough amps in it for the job. Tired starters ,poor connections,undersize batts and cables will cause poor cranking on 6V. And 6V systems do crank slower than 12V normally.

 

I amabout 80% certain that he did NOT convert it because he said he tried the 6v and the next day bought a 12v to put into it to make it better. So i guess i am gonna have to go and check out the starter and if that notthe problem then im not sure what is. maybe some faulty 72 year old wiring. I was thinking about converting to a 12v system eventually but maybe ill have to do it sooner than planned

 

Johnevans, maybe he is just used to hearing and seeing new cars start so it could be fine and he is just impatient. I am hoping that is it.

 

All 6 volt cars of that era sound like the battery is about to die, even in top tune.

12 volts in a 6 volt system will damage most of the stuff, gauges, lights, relays, voltage regulators....

 

If I was you, I would hope that he hasn't fried everything. Short 12 volt burst to say jump start a car can be O.K. but if he's been running it, I can't imagine that you have any lights or gauges left.

As you note, it likely needs rewired anyways. I'd be pricing it with the idea that you are going to have to invest some money into it one way or the other.

 

Like it was pointed out, u need huge cables, a good battery, a good starter and an engine that is in good condition. Yes all of my 6V cars turn over slow, but will start. My solution to this issue was a 6V Optima years ago. Unfortunately my battery finally gave up after 12 yrs. But while it was working it had a 950CCA rating and it showed by starting those beasts really well.

I would certainly look down that road as far as replacing the battery. Also the 12V battery won't charge right with a 6V generator and regulator. That and all the other stuff mentioned might make you stick with the 6V system.

 

damn... he said he has driven it around with the 12v in it so the gagues and stuff are probably shot...

 

I had a 6 volt VW Baja Bug that turned over slow. I changed everything on the car except the starter to 12V.. Car started like a champ...Used it for 5 years and sold it. Starter was still good. Got to change coil, lights radio etc. to 12 V....

 

car doesnt have radio so thats one less thing to change i guess

 

Hmm, have you ever tried to plug a microwave (110V) into a 220V outlet? Doesn't really heat up that Hot Pocket any quicker....uh, actually, not at all.
Can you say "ZAP"?

 

yeah that what i was afraid of

 

well the car will be picked up for transport tomorrow morning and should be to Houston by saturday... so i guess i will have to wait till then to fix it

 

6 volt wiring is heaver gauge than 12 volt, so the wiring, if in good shape, was not hurt. The same goes for the starter. It will operate fine on 12 volts. Hopefully the gauges weren't fried by the automotive genius. Good luck...

 

thanks vertible. that means all i have to worry about now are the gauges. This guy has been one problem after another. first he screwed up the brakes by pulling the master cylinder two days befre the car transport was supposed to come. if the transport hadn't been 3 days late it would have had no brakes. transport should be there tomorrow. he got the brakes on and bled a few hours ago.

 

Be sure to post some pics and tell us what you have planned.


.

 

okay i will. I have never really seen the interior of the car so i figure i will have to redo that first, then change the head and intake on the 201 six. I might end up switching engines to an sbc(dont really want to) or a pontiac engine from the mid 60s, but i wouldrather keep the original engine. just dont know how easy it will be to find parts fairly cheap. Okay i got completely off topic but yes i will post some pics. it is a taxi and the taxi sign should still light up so i am excited.

 

If the car is a '37 Plymouth the gauges are probably mostly mechanical except the gas gauge , so you lucked out there . The ammeter is just that , it measures amps so won't be hurt . (12V uses fewer amps anyway) . As others have said the starter will probably live forever on 12 V but the coil and capacitor may be history , but then again they are easy to replace .

 

thanks bob. I really have no experience working on cars older that 1964 so this is gonna be a big learning experience. I can live without a gas gauge for a while and if the coil is the same as on mid 60's cars then that is easy and never really had to deal with a capacitor so ill learn how to do that...

 

<b>I might end up switching engines to an sbc(dont really want to) </b>

Good, then don't.

 

yeah i probably wont

 

you can cheat a 6v system by placing a 8 volt battery. Your starter will spin more freely and wont smoke your sensitive 6v components. See your local tractor supplier.

 

oh cool. i didnt even know they made 8 volts. might try that

 

dude its cool.... Ive heard all this talkity talk crap bout how you need to convert all this stuff over, and how much work it is. I have put a 12 volt battery in atleast 8 different 6 volt cars to drive them home cause 6 volts dont last long and if you have to crank the motor alot to get it started yer fucked! as long as you dont run it for too long its cool, but you do need to change the bulbs, put a resister in line for the fuel gauge, put a voltage reducer in line for the blower motor, and put a 12 volt coil in it. Also easiest way to deal with charging is to put a gm alternator in it. Oh and disconnect the voltage regulator! it makes a hell of alot of banging noises with 12 volts runnin through it!

 

thanks diesel, that means there is a chance that the fuel gauge is not fried yet.