Actually, the damage is done when you reconnect the battery ~ I don't recommend it but if you disconnect the ground cable and tuck it down behind the battery where it cannot connect and the engine still runs, the alt/ge is good , go SHUT THE ENGINE OFF before re connecting the ground cable .

This was part of my GM factory training long, long ago .

They taught us lots of things you're not supposed to do because if you don't do them *exactly right* you'll damage things .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Good grief. Mechanics do stuff that makes engineers cringe. And they're taught how to do this cr_p in school! Here's an article that explains why what you've just stated is exactly wrong. When the load is dumped, the alternator creates a voltage surge that's rapidly dissipated in smoke and heat. You've just described an excellent procedure for creating endless threads about mysterious problems with brand new alternators and electronic components.


https://en.wikipedia.org/wiki/Load_dump


We used to see this a lot in old Jags that used the Lucas "helmet" battery connectors. These were famous for coming loose, which would result in the premature death of a very expensive vintage alternator. You never ever want to disconnect the battery from a running engine.

I'm going to say it again:
Mxfrank, your posts make my life educational and entertaining.
A genuine two-for-one.