Porsche Repair Questions? Ask a Mechanic for Answers ASAP
Check or replace the fuse #18 in the central electric.
Here is the Charging System Wiring Diagram. Make sure you have battery voltage with the key off at the B+ terminal on the alternator and also battery voltage at the D+ when the key is on run, engine off.
Charging System Wiring Diagram
Did that answer your question? Did you get a chance to check out those things or are you going to wait until tomorrow, since it's late?