[Dave Colangelo]

First clean all your grounds, I have found that this has solved many electrical issues I have had in my Porsche's. The haynes lists there locations, or just look for a bunch of brown wires bolted to one location. Take the bolt out, clean all the tabs, clean the bolt, and sand the area on the chassis to clean metal. Every thing should be sanded to clean copper.

Next make sure you are using the right fuse. When I got my 924S it had some wrong fuses in it and they would blow every so often. I think the haynes manual has the chart if not I have it some where ill look it up.

+1 for checking other things on the line. It sounds like there is a fault that is allowing it to draw a ton of current and blow the fuse.

Along with cleaning the fuses clean the tabs in the fuse panel as well. They corrode and can create issues. If you can check the back of the fuse panel and make sure all connections are clean and not shorting out to each other or ground.

Regards
Dave