1976 Other Volkswagen Models Battery drain and Alternator li

first " start the car and while its running " check it with a volt meter you shuold get 13.5 to 14.9 volts {eng running }....if you do" youralternator is good .....if not turn it off and check it for a parisitc drain ...disconect the ground [black ] cable then get a test light " connect one end to the bat post and one to the ground cable if it even faintly glows you have a short....good luck " i hope i helped"