The Stovebolt Site Forums The Shop Area The Electrical Bay Stovebolt 6 volt charging system, to upgrade or not....

Went to take an enjoyable cruise and in my preflight inspection I noticed the 49 3100 was heavily dischargeing @ idle and wouldn't charge at high rpm.
So I started troubleshooting and didn't get to take my enjoyable ride.
I soon was able to trace the problem to the generator. With the field grounded I was getting 0 volts out of the Arm terminal. I disconnected the wireing, same same.
Pulled the 6v gen and found the brushes were worn to nearly knubs and one was somehow jacked to where it wouldn't make contact w/the commutator.
So I clean up the commutator, brushes, holders, test the fields etc., put it back together, ground the field term, hook a VOM to the Arm term and my bench test shows it producing up to 14 volts when spun rapidly w/an air wrench.
I'll be picking up a new set of brushes from a FLAPS this afternoon. So I should be back in operation tonight.
Question, now that I'm into the chargeing system, what is the lowdown & dirtiest, cheapest, 12 volt alternator conversion that anyone has done?
Are their kits or does one need to assemble the parts?
I know I'll have to swap out all my lamps, add an ign resistor and also a voltage reducer for the gauges/fuel sender.
Just curious to see how others faired w/their upgrades.
Dave

Put a 6v alternator on it (I put a one wire 6v alternator on my '38) and be done with it. Unless you're wanting to run a bazillion watt stereo you can put in a step-up (available on ebay for about $60) that will run most 12v accessories. I installed one on my '38 to run my GPS and it works great. If you choose to 'upgrade' to 12v my experience is that you don't need to put a reducer on the gas gauge. Years ago when I converted my 55.1 panel to 12v I never even thought about needing a reducer and put over 100K on the truck after the conversion without any problems with the gauges at all. It won't hurt to put one on if you're more comfortable with it that way but IMHO it's not necessary.

I am converting to 12 volts. I elected to go with a 3 wire alternator as I wanted to ensure the battery gets charged at idle. 1 wire alternators require some RPM to get them excited and produce voltage. I recommend a voltage reducer on the fuel gauge. I will be using a 6v IC reducer mounted to an aluminum heat sink.

The other thing I don't like about AD wiring is the lack of fuses and ground circuits. So, I plan on fabricating a ground and 12v bus. The positive bus will be energized through a relay via the key switch. I plan to run the A/C, radio, and PA (my son insists on this and he paid for it) systems via the added electrical bus. Oh, almost forgot...since the alternator is internally regulated, I plan on removing the guts from the firewall mounted voltage regular and mounting a 4 slot blade type fuse block in the can. Easy fuse access and looks original.

Good food for thought Tiny. I've been doing some more research via the WWW and theres a fellow that modifys the 6v & 12v gen housings to hold either a 6v or 12v alternator. It looks like a gen but is really an alternator. I also found a source for a std 6v alternator.
In thinking further, at this point the only "need" I'd have to go to 12v would be to power a sound system. But until I do some body work and add beau-coup sound insulation I wouldn;t be able to hear one anyways

DavidF. great idea on using a relay to control a "switched" power buss. I also like the reasoning for a 3 wire alternator.
Great input.
Dave

A battery will get charged at idle with a 1-wire alternator, as long as you have "excited" the unit by once revving the engine to 500-1200rpm (depending on the alternator).

Once the 1-wire alternator has been "excited", it charges at all RPM.

Shes up and chargeing again. Gotta give kudo's to an engineering and manufacturing mindset that produced this old generator and made it so easy & cheap to repair under a shade tree. (actually a heated garage but thats beside the point ).
A $4 set of readily available brushes, some cleaning fluid and sandpaper, is this a great country or what!

I've thought of a few more reasons to go 12v so I believe I'm going to start amassing a stash to go forward one day.
1) modern audio eqt.
2) faster starting
3) brighter headlights
4) brighter LED parking, tail & brake lights.
5) less expensive 12v blower motors
6) 12v windshield wiper motor
7) fuel injection upgrade
8) electronic ign
9) I'm sure theres more

A compelling list.
But, I also enjoy my old 49 just the way she it too
Dave

I converted my 49 Chev. PU to 12 volt. I sent my original generator to local rebuilder and had it converted from 6 to 12 volt. Works out great.

Good input.
1) the only thing I don't like about the 6 to 12v power booster is that you have to have a 9v battery to maintain the programmable settings of the radio etc. But w/that said it's not a deal breaker as my home alarm clock uses the same for power failure memory retention.

2) In my experience, 12v definitely spins an ICE over faster than 6v. Altho my old 6v pos gnd Ferguson TE20 could spin the engine over just enough to start even on the coldest mornings.

3) my 6v headlights are bright enough but, 12v is brighter IMHO.

4) Was unaware of 6v auto LEDs, I'm definitely interested in this.

5) yeah I've seen and priced them when I thought my old heaters 6v blower motor was shot. Found out I could source new 12v motors locally while the I would have had to order the 6v. Gotta include shipping....

6) Glad my vaccums work

7) just because Why spend my spare time and money rebuilding, maintaining and operating obsolete machinery?

8) actually I'm really fine w/points. Altho I do like the idea of a constant unvarying dwell that requires no periodic adjustments. I haven't priced out 6v units.

9) I've also heard the change to 12v was to get better/faster cranking of the higher compression engines that came in vogue at the time.

The bottom line is it's yours, do with it as you please. In my case keeping my '38 close to original, with all of the warts and issues that entails, is part of the charm of driving a 70+ year old vehicle. I love the vacuum wipers, the whine of the straight cut gears, the squeaks/rattles and the rough ride. My AM radio is OK even though all I can get are talk shows and moldy oldie country. I'm preserving a small part of history. A good battery and clean connections provide me with more than enough starting power. My headlights are plenty bright for the 50-60 MPH I drive. I do have a bit of concern with the one tail light but not because of the brightness. Using the best bulbs available make my 6v tail/brake light VERY close to that of a 12v 1157 bulb. Since one tail light is harder to see than two I keep a very close eye on my mirror when driving. I'm quite attentive to what's going on behind and around me.

wow, looks like my last post looks pretty senseless now that the post I was responding to has been deleted for some odd reason........ I guess I'll use the "quote" function more...
Oh well I'll leave it as I won't change what I've already posted once someone has responded to it....

Dave

I have 1 tail light also on my 47 truck. Definitely need to keep an eye on the mirror as your driving.

Reasons to keep a 6 volt system:
1, Stock, what it came with.
2, Parts are easy to look up.
3, If it works, why fix it?
4, Belts are the same as the parts book says they are.
Reasons to convert:
1, Lights are easy to find.
2, Accessory's are easy to find.
3, It might start better...maybe.
That is about it. Good news? You get to choose.
Ways to convert?
1, 12 volt generator.
2, 12 volt alternator, a: 1 wire. b, with external regulator.
The rest as they say is in the details. Want a modern ignition? Convert. Want a modern sound system? Convert. Want a stock radio? Keep what it came with. Of course there are ways around each of these but it gets more complicated if you add up converters to run a new radio or sound system on 6 volts. Or if you run load resistors to run a 6 volt heater motor and gas gauge on 12 volts. Your truck and..your choice. What do you want it to look like? Original? Custom? Or are you just trying to be dependable? Enjoy this is the fun part.