You still have the alt wires going into the Ammeter on the dash? take off the main alternator wire. leave it off. Run a NEW thick gauge wire from Alt to Battery positive and see what you get.
How are you determining your alt doesnt work?
I checked using a multimeter. Alternator is only showing battery voltage. I also did the negative battery cable trick. If you pull the negative and the car shuts off it’s the alternator. Also I don’t have anything going to the voltmeter in the dash.