check that the 2 small wires that connect to the voltage regulator are not broken, one wire in them is the switch on wire and also acts as sense wire for voltage, the other is charging lamp.
Also make sure the big wire connector near the the left side shock tower is in good shape, it usually burns off from corrossion etc.
When you are confident your car is good - check the alternator itself - replace bad parts as required, - if the slip rings are shot then get a new rotor which has original windings. Its not rocket science. Dont try to shotgun it.