MTFCA Forum

I have read several posts both pro and con on installing a 12 volt alternator in place of the standard 6 volt generator. I know I plan on changing light bulbs and according to some taking a chance on the starter bendix. What I think I read in one or more posts is that I also have to change the wires on the amp gauge and change the original negative ground to positive ground. Is that correct?

Lemme just say this...I put in a 6V alternator, and absolutely LOVE it on my Fordor. No more dim headlamps, charges good for a few minutes after cranking the engine, backs off to about 1-2 amp charge the rest of the day no matter what. So why go to all the bother switching to 12V? This alternator hooked up in less than 5 minutes. Think about it.

First thing is there is no positive earth alternators, maybe a few in the 1960's but not the done thing today.
I don't know if someone is still making the vendor alternators the same way today but there was some that had the drive gear held on just with a roll pin, that would work it's way out and make a nice mess of the timing gears. So make sure that the gear is screwed on.
I believe the one wire bolt on alternators from the vendors are set to Amp output to match the old generators function, so can't
see a reason for any wire changes.

I agree with Tim. I replaced the generator with a 6 volt alternator from Buckeye Electric four years ago and it has been totally reliable.
Rick Schrage

Go with a 6 volt alternator as others suggest. I have had 4 on 4 different cars. Delco, Becker and Ohio Auto Electric, all work well and require no additional wiring modifications. Early on, they did not have a shutoff when stopped. The battery would drain down. That problem has been addressed and the new ones work well. No problem running a distributor in keeping the battery charged.
Just my opinion.

What are the advantages over a standard T generator fitted with a Fun projects regulator?

Allan from down under.

None

they will both keep your battery charged

in fact, the generator will charge a dead or low battery, and an alternator will leave you at the hotel waiting for the trickle charger to do it's thing

Dick. Another option. keep Your current 6 volt system and generator. switch lights over to 6 volt LEDs. brighter than incandescent and halogen bulbs with a fraction of the amps. When I switched to LED. headlights current went from about ten amps to so little You can barley see the needle move. and now Your original generator should have no problem keeping up.

Thanks Scott. Sometimes the obvious needs to be pointed out.

Allan from down under.

Thanks all for responding. I didn't tell the whole story in my request for info. The reason I am going to an alternator is that the current generator has failed. I have looked into a replacement generator and the cost of a rebuilt generator is a lot more than the new alternator. I could go with a 6 volt alternator but the recommended advantage is the 12 volt so lights are better and I could also use the 12 volts for other accessories. I have ordered a 12 volt alternator and it is scheduled for delivery tomorrow. Now, back to my original request for info. The current system is the original generator with a 6 volt battery. I have a new 12 volt battery ready to install. Since the original system is 6 volt, do I just continue to have the negative ground and do I need to change the amp gauge wires? Dick C.

TWrenn wrote: ↑

Sun Jan 24, 2021 5:53 pm

Lemme just say this...I put in a 6V alternator, and absolutely LOVE it on my Fordor. No more dim headlamps, charges good for a few minutes after cranking the engine, backs off to about 1-2 amp charge the rest of the day no matter what. So why go to all the bother switching to 12V? This alternator hooked up in less than 5 minutes. Think about it.

I totally agree with those advocating a 6 volt alternator for a "driver" car. Unless your adding air conditioning and a lot of accessories that require 12 volts, just go with a 6 volt alternator. I don't know of any 6 volt that don't mount in the generator location. I do know a guy who advertises on EBAY that rewires the old style Delco alternators to 6 volts, but unless you are using the generator location to drive an oil pump or something, you might as well mount one of the readily available 6 volt alternators, there.

Be very careful with the alternator's gear mesh with the cam gear. Birdhaven's unit has an exact gear mesh with the cam gear. You will still have to add gaskets to get it correct, but at least the gear mesh of alternator gear and cam gear are exact. The same can't be said of some of the other units out there. Had one from a vendor I won't name that didn't mesh correctly regardless of shimming. Finally I benched the unit and pulled a cam gear to check the mesh. They didn't match close enough to install. Double check it first.

After running an alternator for a couple years, I went with LED lights and rebuilt my original generator with the Fun Projects regulator on it. Set the third brush at 8 amps. Plenty of amps to power all the lights (draws barely over 1 amp when everything is lit up) and still recharges the battery quickly.
No regrets at all.

I swear to God- if vendors had a "bolt on" Ginsu knife set for the Model T people would buy it and champion it's greatness...

Tim Rogers wrote: ↑

Mon Jan 25, 2021 8:00 am

I swear to God- if vendors had a "bolt on" Ginsu knife set for the Model T people would buy it and champion it's greatness...


silly.png

Amen.

I don't wanna step on anyone's toes re the LED lamps, because they certainly are super bright with no power draw.
But, I've yet to see the "configuration" of the light "throw"....how far it projects down the road. Frankly, at least in the case of the
power sucking Halogen's, I've experimented with one halogen and one std. bulb simultaneously, and the stupid std. bulb actually put out BETTER LIGHT distance wise! If someone can provide good solid picture proof of how "far out" the LED's go, it would be nice.
All I know is, my alternator puts out fantastic enough with no other changes for what little night driving I'll ever do. And of course, that's a big part of the argument...how much, how often do you want/need driving anyway. 'Cause you still got a very dark rear end with tiny little red spots for todays distracted drivers to think about. Personally, I just stay home in the dark!!

I have one of the Fun Project regulators on my '23 Runabout and am very happy with it. I just went to purchase a second one for the '14 Touring and found they are back ordered with no delivery date known. The same with the plastic "wood" kit for the coil box & a number of other Fun Project items. I sure hope this is temporary as this outfit sold well engineered & crafted items that actually work.

Don’t do it ! A friend of mine installed a alternator that could never be in mesh with the Timing gear. The gears howled very loud. He refused to remove it...it slowly ate up both gears. I believe the alternator was from Buckeye.

Hi Dick,

So far, I haven’t seen an answer to your questions. When you install the alternator that you already bought, the existing wiring will be fine. Without changing anything else, all of existing wiring will be “overbuilt”, with the same current draw, the amperage will be halved when you double the voltage. I’m not aware of any need to change to positive ground.

As far as light bulbs, you can safely double the wattage and the load on the wiring will be no greater than with the original 6V bulbs. The starter will still work, at least for a while, although a number of folks have warned against damage that the over-volted starter can do to the bendix and/or flywheel. And running the original starter at 12V will eventually cause the starter to fail, maybe sooner, maybe later. There are bolt-in 12V starters available from our regular vendors, when you get around to that change.

I’ve been running a cam gear driven, 1 wire, 12V alternator on my “temporary” late engine in my ‘14 touring that was put in while the original engine was being rebuilt. I have had no issues with the alternator, the 12V starter, or the hidden solenoid to run the starter from a simple press button on the bottom of my coil box (I can press it with my right foot). I’ve got no electric lights, so no issues there. The brass top coils work great on 12V battery or mag. The battery is under the rear seat, since the frame has no provision for the standard T battery holder. All of this will be reversed when the original non-electric engine goes back in the car. At that point, I’ll go with a small “motorcycle” battery running the coils only. That battery will be charged with an external charger when needed.

All the best for your project.
Eric

I added a 6volt alt.4 years back.. The only problem the roll pin broke on a tour in Kansas the next summer. I drilled the the hole out to an 8 mm set screw with a little lock tight on it. Has been just fine for 3 years. No problem hooking everything up. Clyde.

Eric, thanks for your insight on this issue. I am aware of the potential problem with the starter. I have a good friend that has a business focused on repairing Model T's and he has converted many to 12 volts. His personal T's all run on 12 volt. He has never had an issue with the starter. Of course I have always said he is a lucky sob and maybe some will rub off on me!!! Dick C.