Used alternator making a grinding noise?

Yeah, the copper coils were all black and diodes were melted. It was whining when put on the gas the whine for louder, so I figured she was toasted. So, I got a used one of eBay as soon as I got it I spun the pulley and loud grind is heard. My question is, could the grind be from sitting and maybe running it a bit it will go away or not take the chance just get a better one? I make 50 to 100 mile trips once a month and don't want to get stranded anywhere that far from the house. But the alternator I took off created weird symptoms, I was that the electric inside the car would go off three seconds later it would come on the go off like cycles, but old alternator seems to put out voltage just to unsteady sometimes 11 v or idle 12.2 startup 8.5. So, I figured it is the root of the problems. Oh, I saw wetness on the battery like it overheated or boiled sometimes never smelled anything so not sure. Thanks for replying.

Thank you anyhow the way this fiasco started was driving all of a sudden everything inside of car went of car started running horrible then all of a sudden everything came back on and it started doing that like it was cycling so we take car home data port spent work so can't scan the car about three hours after that we used the car to make a short trip where I live no way to walk the closet palace 3 ron4 miles away I am 53 not in good shape so any way another 4 hours goes by we were going to go to the store but we hear aloud ticking noise pop hood put my hand on intake manifold and can feel the ticking inside of car ticking coming from under dash and driver electric seat try to start car no reaction check battery 8.7v take neg cable off charge battery still had everything turn off when giving gas let off gas everything come back on so check when car starts battery 13.9 v turn key drop to 10.7 and decide then alternator is bad I hope I am on right track and don't have same electrical issues after I get the new alternator any ideal what may have cause the main electric issue of turning off and on thanks for helping out.

Battery sitting usually is 12.3 to 12.8. When the car is running it's at 13.4 to 14. Since dash and all electrical goes off then back continually it had dropped when starting the car the battery drops to 8.5 to 10.V and alt test at 11v then we went to bed woke up to go to store battery completely dead and it was making ticking noise I know it was voltage drop so low it's all it would so the alternator has had a whine but we actually smelled wires burning htw the alt whine got real noticeable and when got close to the alternator could hear it loudly and a clicking noise. So, I pulled the alternator and all copper in the alternator was black and smelled bad. So, I figured alt is done but looking at the battery it was wet on top, so I know it was from battery. My question is, can an alternator do that much when it goes bad? I had just gotten back from a 1143-mile trip, so it was a blessing that didn't happen until I got back home. It started by all the dash gauges going flat, A/C, everything inside quit working. The car behind me told me, and my backup lights came on the it acted normal but when I would give it gas all electrical would go out few seconds later come back on then out again and on, all the way back to the house. It did that and idle for rough but figured it was due to electrical problems. I need to know if also you can tell me where the fusible links are so I can't est them to cause now data port is dead it fried Myt obd scanner so if it was the alternator I hope it didn't hurt anything but need to know where fusible links are thanks for replying to my messages it's a lot nit I try to give every detail I can.