Autobahnzerreisser

Hello.
I try to fix my alternator these days. But somehow it doesnt charge the battery at all. I took an non-mechanical universal voltage regulator but it doesn't work at all. I think somewhere in the wiring is a ground fault and that would also explain why my old alternator died. Is there any possibility to fix that up without rewiring the whole car. I thought about a one wire alternator which charges only with the plus wire??