Why does this wire Spark?

[Purdy Swoft]

Because the alternators that are offered for 12 volt use on the model A are all negative ground. I run my roadster 12 volt positive ground with the original unmodified generator and no changes to the original wiring is necessary.

[Y-Blockhead]

Originally Posted by Purdy Swoft

Because the alternators that are offered for 12 volt use on the model A are all negative ground. I run my roadster 12 volt positive ground with the original unmodified generator and no changes to the original wiring is necessary.

What Purdy Said...

Purdy, with your set up do you need to run a regulator of some sort, such as the one from Fun projects http://www.funprojects.com/products/10505r.aspx

I run a Powermaster PowerGEN, mainly because I hate the look of a alternator on A Model A engine. If it ever goes out, I may put the generator back on with a Fun Projects regulator.

[Keith True]

I've only seen one person so far that that has posted the fact that there is a parasitic drain with the one wire converted alternators.It is tiny,I have one on a wood chipper that will still start in the spring after sitting all winter.I have one on my big air compressor that seems to sit a year before it is drained off.My loader has one that drains in about two months,but that one has a big spark when the wire is pulled off.I know the alternator has a problem,but it does charge and I just use the cutoff switch.If your alternator drains the battery in a couple of weeks,or makes a big spark,then there is something wrong.That parasitic drain won't register on an ammeter.

[Purdy Swoft]

Originally Posted by Y-Blockhead

What Purdy Said...

Purdy, with your set up do you need to run a regulator of some sort, such as the one from Fun projects http://www.funprojects.com/products/10505r.aspx


I run a Powermaster PowerGEN, mainly because I hate the look of a alternator on A Model A engine. If it ever goes out, I may put the generator back on with a Fun Projects regulator.



I do use the Fun Projects can style voltage
regulator. It will still work with just a good cut out but will have no voltage regulation. I would reccomend the Fun Projects regulator on any model A generator. It looks like a cutout and is just as easy to install . The Fun Projects voltage regulator is offered in six , eight and twelve volt versions and can be had in positive or negative ground. For the six volt version you need to adjust the third adjustable brush for a 15 amp maximum charge rate , The twelve volt version is set for a maximum rate of 8 amps . John Regan , the makertold me that I could set mine for a maximum rate of 10 amps if I felt that I needed it for brighter lights. I use the 35 watt halogen bulbs that fit the original sockets and they are plenty bright plus two tail lamps. I run mine pretty much like original . If a person wants to run a lot of high amp draw accessories , this may not be the best choice . One of the things that I really like about this set up is that the generator doesn 't have to be dissassembled to install it .The other voltage regulators that are on the market still require the use of the sometimes troublesome cut out . The Fun Projects regulators have no points to stick like the original cutouts do . The Nurex internal voltage regulators that take the place of the third brush are not available in 12 volt I have had years of trouble free service from the six and twelve volt versions of the Fun Projects voltage regulators ...

For some reason I'm having problems getting this message to post ...

Try this, Maybe it will post

[Purdy Swoft]

Originally Posted by jchochole

Purdy- yes, there is indeed a hot yellow wire (that's the sparker) that goes to the alternator. Looking at schematics with colors, the wiring looks in order in the terminal. So, just not sure why I am getting a good spark at the alternator post.

Read Keith Trues post # 23 Keith knows his stuff . The one wire alternators can and usually do have a small parasitic draw . Its not usually enough to cause a problem if the car is used on a somewhat regular basis but could cause a spark at the terminal when the yellow wire with black tracer is connected .I'm not making any suggestions only because if there are other problems I don't want to cause more . Good luck and it will probably be OK .

[jchochole]

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I am leaning towards buying a 6V Positive Ground alternator, and going back to a 6V positive grounded battery, that way I can use all the existing bulbs and stock ammeter in the car.

I don't need a 12Volt system. It looks like if I remove the ballast resistor and drop a 6V battery back in for positive ground, I am back to stock.

Does anyone thing I am missing anything?

[jchochole]

Okay here's the answer, I ran the 12V alternator to get it bench tested and it is stone cold dead. Wouldn't even accept voltage into it. That's why it sparked.

[Purdy Swoft]

I would get an original generator and a Fun Projects voltage regulator . Then you would have voltage regulation . You could choose the voltage by which voltage regulator that you chose . You would still have the original look even if you chose to keep and use your 12 volt battery . I use the original type 20 amp ammeter with my 12 volt setup . If you are running a 30 amp ammeter it would still work . The ammeter only registers amps , not volts. You would need to remove the ballast resistor and use a 3.0 OHM coil. the coil would cost less than buying a new six volt battery even if you used a pertronix flame thrower coil like I use on mine . I chose to convert to 12 volts for a more powerful and reliable electrical system . Twelve volt batteries and components are readily available almost anywhere and usually less expensive . Twelve volts cranks quickly . Light bulbs are cheap , especially if you use the original style bulbs like all the vendors sell for 12 volt use . I chose the 35 watt halogen bulbs that fit the original sockets . My lights are brighter than original . It may sound complicated but it really isn't . Just a thought .

[Bikerider58]

I have not had my A long, and now have a 6v alternator, LED tail lights, 12v power supply for gadgets and LED driving lights. If I would have thought about it more before buying the 6v LED tail lights, I probably would have just gone to 12v with regulator for all the reasons Purdy states.

The wiring is good except for lack of fusing. I added a main fuse and fuse block splitting the circuits. Stuffing the runs into asphalt cloth loom is a pain, but needed to look right.

Make it your own and have fun with it.

[Y-Blockhead]

Originally Posted by Bikerider58

I have not had my A long, and now have a 6v alternator, LED tail lights, 12v power supply for gadgets and LED driving lights. If I would have thought about it more before buying the 6v LED tail lights, I probably would have just gone to 12v with regulator for all the reasons Purdy states.

The wiring is good except for lack of fusing. I added a main fuse and fuse block splitting the circuits. Stuffing the runs into asphalt cloth loom is a pain, but needed to look right.

For my added "accessories" (Turn signals, Fog Lights, Temperature Gauge, etc. I use ClassicBraid by Painless Wiring. It is a split loom that looks (somewhat) vintage compared to others (like corrugated plastic) as seen in the picture in post #22 covering the water temperature gauge line.

[Glenn Thoreson]

That wire should go to the ammeter. If you are using a one wire alternator you need to forget this wire and make sure the alternator wire(s) go directly to the battery in whatever fashion you prefer. You may need to re-route the feed to the ignition switch. Don't run an alternator through the stock ammeter. It's not meant to handle the amperage and will burn out or start a fire. They were bad enough with a 20 Amp 6 volt generator.