can I put a 12 vote alternator on my model t and still use the buzz coils?

Coils will work on 12 volts just fine, in fact better if you are using just a battery. (They work fine a 6 volts too) If you are running the magneto, the two systems are not connected and switching between the 12 volt battery and magneto is no different 12 or 6.

Works great. I did that on my 26 Roadster. I did run a #8 wire from the alternator to the battery terminal on the starter switch. This will help limit the current through the stock wiring harness. PK

Yes, I have a 12-volt alternator electrical system in my '15 Touring; retro-fitted, of course. It's independent of the magneto/timer system, but when using the battery position of the ignition switch, the 12-volt battery powers the coils. After the engine catches, I switch over to the mag. For your '25, I would also humbly suggest switching to a 12-volt starter as the greater voltage is hard on a 6-volt starter.

thanks everyone for the information.

I too vote for the "12 vote alternator"! In regards to changing over to a 12 volt starter, I have always had read that the 6 volt starter's windings can handle 12 volts better than a modern 12 volt unit due to the fact that the 6 volt starter is typically wound with a heavier gauge wire. I've converted several cars, trucks and tractors over to 12 volts through the years and have never had a problem with a starter that was in good shape ( new brushes and bushings, no dead shorts on the armature) handling the extra voltage. I would run the 6 volt unit- if it fails, replace it with a 12, but give it a chance before spending $$$ you might not need to.

It's not the winding's handling the load, it the speed slamming the Bendix into the ring gear coming from the fact that winding's are wired different between 6 and 12.

When I went through my TT some years ago I decided to go with a 12 volt alternator. I know the purists gasp, but my logic was:

1. The starter hadn't worked in over 50 years, it was always hand cranked so that wasn't an issue. I just blanked out the two starter openings.

2. It needed a battery and cables anyway, so pretty much a push as to battery and cables.

3. The generator was shot, no output. I'm not an electrical guy, so a replacement generator or alternator was a must.

4. All the light bulbs were either missing or broken, so again a push. Needed new bulbs, 6V or 12V.

5. Of course the coils buzz a little better on 12 volt.

6. I already owned a 12 volt battery charger, but not a 6 volt charger.

As things have turned out, I got an unanticipated residual benefit. On several occasions over the past years I've been able to use the ol' truck to jump start a modern car. I love the looks that activity produces.

Harold,

As your Model T is a 4-door sedan, the likelihood of other drivers seeing your hand signals from the direction of the right-rear corner of your car isn't very hopeful and that might make your left-to-right lane changes a little bit iffy. _One of the advantages of having some kind of electrical system is that you can mount a set of turn-signals. _This particular kit, designed for retro-fitment on pre-war cars, can be bought with a 4-way flasher option as well. _The signals on my '15 were installed when I purchased the car six years ago and they work great. _The "Ticking Through Time" website is:

http://www.ronsmachineshop.net/Hidden_Turn_Signal_Kits.html

I made the 12v switch 20 years ago on my 26 Coupe. Other that breaking a couple of bendix springs until I learned how to deal with that, it has been the best move for me. Brighter head lights, no more cutout/generator problems, an all around better electrical set up. Henry would have done it back when had 12v battery's been available. He told me so..... Jerry.

RE "12v battery's been available" They were. Dodges were 12 volt up to about 1925 (I would have to look up the year)

Jerry how did you prevent that problem breaking the bending spring.