Rusty Bumper; "¿Why?".[QUOTE said:
You're right, why.
But it is easy if you really want to be a rebel and end up in Model A hell.
Here is why I prefer a 12 volt electrical system. Six volt electrics have been obsolete for over fifty years. Six volt batteries, cables, coils,bulbs and anything six volt is no longer easy to find,especially on the road. Slow six volt cranking doesn't thrill me in the least and neither does dim six volt lights. A six volt battery that is the least bit low won't have enough power to run the starter and fire the points, This can be a real problem if the car is not driven on a regular basis.
A good reason to change to 12 volt negative ground with an alternator is, you can use the quartz halogen bulbs that come in a kit with reflectors. This kit gives headlamps that are safer and ARE just as bright as the headlamps used on modern cars. The 12 volt halogen bulbs cost less and are readily available, so are 12 volt alternators. Six volt alternators are not and have to be ordered from a model A vendor. The original positive ground is more difficult to maintain and if you don't stay right on top of things will cause a slow turning starter and VERY poor lighting. Grounding problems can leave an inexperienced model A owner stranded and confused. How many times have I heard The starter is turning slow and there is no fire to the points?
Everything depends on what you want out of your model A. If you have a perfectly original model A , I would say leave it alone. If you want a more reliable driver that your wife ,children and grand children will be able to use, A 12 volt system could be a serious consideration. New day mechanic-technitions will know nothing about a six volt positive ground system and its unique problems. If you don't do your own repairs, a trip to a restoration shop could leave your pocket book with post partum depression.
I prefer my model A's to appear original. I am running my roadster on 12 volts with the original generator. This system gives VERY fast cranking with power to spare. I use the aluminized reflectors from Brattons and the halogen bulbs from Australia. These bulbs are brighter than model A bulbs but not as bright as the quartz halogen bulbs that require a 60 amp capable system. The 12 volt tail lamps are bright and much safer than the dim 3 candle power originals, Who wants to get rear ended? The model A generator will have NO problem charging 12 volts or more without modification. I use the Fun Projects voltage regulator that looks JUST like the reproduction cut out and can be had in positive or negative ground. All original type wireing harnesses are used and the only changes that I made was to install a 3.0 ohm coil, i2 volt bulbs,and the modern barrel starter drive for reliability. This system doesn't cause any visable modifications. The battery is hidden under the floor boards and nobody will see it or know the difference If a person wanted to change back to original, changing the battery would be the biggest thing, so why would anybody fret?
I have owned and driven model A's with original 32-50 candel power bulbs and they don't compare in any way to modern halogen lamps, even if you have re silvered reflectors and excellent ground. The comment that a person would change to 12 volt rather than replace a faulty wiring harness is ABSURD!!!! A faulty wiring harness wouldn't work regardless of the voltage, GET REAL! Resilvered reflectors are very expensive and a drawn out hassle to obtain, not only that the lights still WON'T be nearly as bright as the quartz halogen bulbs that are offered with reflectors in kit form.
Changing to twelve volt is not a bandaid but a MAJOR improvement for a car that will be driven on a regular basis. I know that a well tuned model A will crank with the weak six volt system but an inexperienced driver will often flood out and kill the battery to the point that it won't fire the points. I have always been a REBEL and damn proud of it. I don't think that being a rebel is a requirment for converting to a NEW DAY reliable 12 volt system. I have No problem with whatever system that a person chooses for their particular application. Model A hell can be tring to overcome some of the quirks of a weak six volt positive ground electrical system. Now how is that for HAMMERING the issue to hell? I'm not mad, just telling it the way that I see it and having fun in the process