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Old 12-03-2020, 07:37 PM   #21
700rpm
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Default Re: Conversion to 12 volt system

I’m with nkaminar. Where do you have your charging rate set? It should be 8-10 amps. If it were me, I’d pull the starter out and bench test it with jumper cables and a known fully charged 6v battery to make sure it doesn’t need service. Also, if your engine is newly rebuilt and not broken in, it may be extra tight. Can you turn it easily by hand? These things are easier to check than converting your system to 12V, which in my 60+ year experience with these cars I have never found to be necessary.
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Last edited by 700rpm; 12-03-2020 at 07:50 PM.
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Old 12-04-2020, 07:36 AM   #22
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Default Re: Conversion to 12 volt system

Been running 12v for years, get a starter wired for 12 volt and install a modern starter drive and you will no longer need to worry about broken starter drive/bolts. Battery has lots of reserve, brighter lights, motor runs better. Also you can run a 1-wire alternator obtainable at any auto parts store. No need to pay $$ for one of those GM alternators converted to 6v positive ground. (you will need to convert to neg ground and related system upgrades and polarity switch on the ammeter, should also be 30 amp).
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Old 12-04-2020, 08:14 AM   #23
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Default Re: Conversion to 12 volt system

Number 1, you have a problem. What you describe is NOT normal for a stock A. Do you have a good quality voltmeter? If not, go buy one. You'll need it sooner or later anyway. Check the voltage on the battery terminals. A. Before you start the car. B. When cranking. C. When car is running at a fast idle. Then one more test, check at the starter lug in all of these same times. Get back to us with the readings and we can give you an educated diagnosis. Otherwise all your going to get is a bunch of wild worthless guesses.

Fyi: unless you spend some serious money on a really good DVOM, an analog meter is better because of the noisy electrical system in an A. A simpson 260 is kind of a gold standard analog VOM. You can get them on ebay for around $50 to $100. They ARE worth it.

Fyi 2: switch to 12v if you want, there are some advantages but FIRST fix the issue thats causing the problem. It will still be there on 12v, but may be somewhat masked. It will then raise its ugly head at the most inconvenient time, like when you're on a trip somewhere a 100 miles from home, on a backroad when you stopped to take a leak, and you have no cell reception, and a bear is eyeing you up... you get the point!
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Last edited by eagle; 12-04-2020 at 08:27 AM.
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Old 12-04-2020, 01:30 PM   #24
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Default Re: Conversion to 12 volt system

Just to add , I use the original style 20 amp ammeter with the 12 volt conversion on my model A and have for many years with no problem .
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Old 12-05-2020, 09:40 AM   #25
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Default Re: Conversion to 12 volt system

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Originally Posted by Purdy Swoft View Post
Just to add , I use the original style 20 amp ammeter with the 12 volt conversion on my model A and have for many years with no problem .
12V loads require only 1/2 the current, so you don't need a 30A meter.
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Old 12-05-2020, 09:54 AM   #26
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Default Re: Conversion to 12 volt system

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Right on !
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Old 12-06-2020, 12:28 PM   #27
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Default Re: Conversion to 12 volt system

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Originally Posted by Badpuppy View Post
12V loads require only 1/2 the current, so you don't need a 30A meter.

And don't worry about whether the 6-volt wiring is good enough for 12-volt. The 6-volt wiring is heavier because it has to carry more amps so it will have no problem with 12-volt at 1/2 the amperage.
More amps = more heat in the wire = need for thicker wire.
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