91 corolla charging issues

hi hello I’m stephen and I’m new to the forum. Couldn’t find anything by searching. I have a 91 corolla with what 4afe and a131l in it. About two weeks ago I was driving and the battery and brake light came on. Alternator and battery were both shot. Replaced both. Then the next day the started quit(it would start the car and when you turned it off you had to wait to start it again..)

So the other day I checked the voltage coming from the new alternator with the battery cable discounted from the back of it. It was putting out 2 volts. Weird because I had it checked at two part stores before this and it tested perfect.

Today I received another one. Checked it and t was putting out 13 volts. I was like alright, this should fix it. WRONG. So jumped the car had it running the battery was at 10 volts while running and the alt. Was at 13 and dropped to 3 and the car died.

My only other option, is something in the wiring has broke or grounded out.

Has anyone had experience with this? I’ve never touched wiring in a car except to just unplug the harness when I had the motor out of the car two years back.

I’m at a loss and I need some sort of insight into the problem.