Here's the background. I fired up the carfor the first time a few day's ago and noticed the alt was NOT charging. I pulled the engine and removed the paint between the bracket and the alt and the fan housing to the case. Checked it with ohm meter and all was good.

I got the engine to fire today and at idle there is no charging going on. During the 2500RPM cam break in there wasw 13.65v

After the break in, at idle, the light on the dash was on and there was no charging.

I searched the archives and noticed Sir andy had the same issue and there was mention of a diode prob..

Could I have fried a diode when there was no ground return on the first fire up???

Thank's, Keith

Sure. Alternators, unlike generators, need to see a load (typically the battery and the car's electrical system).

I took one I bought on eBay to a local AutoZone, and found out they don't have the right equipment to test type-4 alternators, so take it to an regular automotive electrical shop to test it or a repair evaluation. They tested mine for free