I've always (well maybe not always) thought that pattern recognition is an important part about being a good mechanic, a good troubleshooter. Modern vehicles are incredibly complex and sophisticated, and I certainly don't envy folks that have to work on them. But, if you've ever pored over vintage shop manuals, owner's manuals, repair manuals going back to the earliest days it becomes obvious that the exact same principles are at work. Compression. Ignition. Fuel. Having a solid background of knowledge and understanding of the basics is invaluable when trying to troubleshoot more complex systems. What I'm getting at is a modern mechanic who has been mostly trained to simply scan for trouble codes and throw parts at it (it's remarkably easy to spend other people's cash) would improve diagnostic skills by reading those ancient Motors Repair and Ford newsletters and the rest of it. The modern stuff has the exact same issues and responds exactly the same way, with a huge overlay of bells and whistles.

One major difference between alternators and generators is the Cutout. To prevent backfeed, once the charging voltage drops below spec the entire electrical system is supported solely by the battery. This is why a heater fan would slow down. A physically large battery with a lot of reserve capacity is necessary, or the battery will tend to get smoked. Most people concern themselves only with high CCA, but there is no free lunch. I have not had any problem issues with a a Pertronix Ignitor and a generator whatsoever for many years, and the wideband O2 sensor works excellent.

People tend to be both unrealistic and misinformed about older technology. To hear them put it, back in the day everyone was driving millions of miles annually at night nearly blind with dim, yellow headlights, drum brakes that didn't work, batteries that never charged, and stranded by the side of the road constantly due to those points and condensers.

Right on Tedster!

"FREE SAMPLE"

I agree with Tedster, if it worked in the day, it can work today and it will. I love motors and generators, it was my occupation as related to heavy industry. But, I installed a Ford alternator on my 64 F100,  it works perfect and installed it in such a way as to make it look like it belongs there. I did it because it became very annoying to have all the lights, accessories etc. quiet down, dim down, slow down when ever the engine was at idle. I wasn't sure how modern components would like the voltage swings, like an MSD box or a wide- band O2 monitor for carb tuning and as mentioned above, an alternator will be necessary for A.C in the future. As a second choice I would have installed a Power Gen mainly for the generator looks. However, nobody knows the Ford G1 alternator didn't come from the factory that way.  Except, of course, all the folks on this excellent forum know better.


64F100 57FAIRLANE500

Further re Generator's. If your collector car isn't driven fairly regularly, for instance mine isn't during winter months, keeping the battery up with a generator can be a problem. According to my local Battery shop, batteries don't like to be charged up & then let go down low repeatedly. It can lead to problems. They recommend using a "maintainer" in winter storage. The basic ones are not expensive & keep a low charge on the battery, preventing  cycling up & down. It seems to work fine..      


Paul

I think what anyone "needs" can be expanded, if you think about it - after all nobody "needs" a 75 year old car or truck, do they? I kept the generator on my truck because they work, and that's what it came with in 1964. For my part, I would probably not install a generator if it already had an alternator, but in the same vein I would not convert a 6 volt car or truck to 12 volts, I like to see some of the old technology up close and if it worked for them, I can probably make it work for me. But (surprise!) alternators replaced generators for some good reasons. Modern accessories and current hungry devices can't be used with a 30 ampere system. Air conditioning, for example. And generators are a maintenance item. They are reliable, but they need periodic maintenance and servicing. Not everyone wants to do that. In fact hardly anyone. That may be one reason why they have such "bad luck" with generators. They will fail spectacularly at some point without periodic attention. There is a learning curve to their Mysteries, and people's eyes glaze over. They want to drive their collector car or truck, not wrench on it by the side of the road. Them electrons is "Here There Be Dragons" stuff to a lot of folks.

It works fine and after 3 years and about 15K miles I have had no problem or concern with it.

Exactly. 

The generator light will always come on at low RPM.  

If your car is, and will remain, 100% original, and your generator light does not come on at low rpm, probably nothing.

Why is an alternator needed? what's wrong with a generator?