ALT light on

Replace the Diode Trio.

55 amp alternator Bill,

purchased it rebuilt, installed when  I added AC to Javelin.

Still have the 35 amp Alt, original to car, still works,

Still using original voltage regulator.

Hoping to check things from your info tonight.

I did read your posts at beginning of electric section about alternators too.

Thanks Bill !

O'Reilly can get them in rebuilt, 55 amp. guy said there's 50 of them available.

Ten bucks to ship.  $60.99

Limited Lifetime Warranty

any opinions?

Sure, the price is ok, but referring back to having to go through three to get a good one, and knowing they test them for charging only, and not much else, all I can say is "use at your own risk".

I have a few reman on my shelves, using for cores, and have worked on several that were sent to me - that I discovered were reman, and the parts were wrong, questionable processes used (like painting over rust, weak diodes and so on)

I can't compete with 60 bucks and won't try.  The parts I use alone would be almost that much. 

A recent thread also showed someone with the alt light glowing - and after some back and forth, found it was the replacement alternator, he tried another and the light stopped glowing. 
That tells me the first ones had weak isolation diodes, not tested for the correct voltage drop under load.

You will find people here who have gone with such things and have had good luck. That's how it goes. Some will say go for it - because they did and it was fine. I can't ever say "they are all bad", only comment based on experience, and what I have on my shelves (seeing first-hand what's inside and how they do it)
I also suspect "your mileage may vary" because a lot depends on the source of the part that the store sells. Some are better than others, for sure.

Billd,

you are a wealth of electrical knowledge my friend.

What I would enjoy knowing are a couple things, as I am beginning to think this is going to be a long drawn out process.

Will it damage anything if I continue to drive the car with the ALT light on.

The battery is an Optima Red Top. I haven't driven it more than ten miles with the light on so far.

If that diode or diodes is failing/failed, does it tend to "cook" the battery?

Other idea, until I can get the 55 amp Motorola repaired, if I put the 35 amp back in, will that kinda keep up with the charging when AC is on?

Motorola's are finicky and few people rebuild them correctly. I almost gotta do it myself, and of course it's summer -  more fun to drive em now than fix em...