all electricity shuh off in my 1985 Porsche 928
I was installing a new radio in my 1985 Porsche 928 and it was working when
fuse to radio blew I believe. I replaced fuse with higher amp one but radio did
not come on again. Soon all the power went off in the car. I have
disconnected radio but no power to the car anywhere now,
You must have shorted something by touching a wire. ONLY replace fuses with the CORRECT AMP same fuse. By using a larger amp rated fuse you have the risk of melting wires and destroying your car's entire electrical system! You should only have power to the radio with the ignition key in the "Accessory" position or when the car is running. Check ALL the fuses with a fuse chart (owners manual) and make sure they are correct size and all good. You mentioned the radio "was working". Perhaps you've tried to install a radio that uses too much power? Remember this car is 1985, so make sure the radio spec power requirements aren't too much for the rated fuse.
Looking for a Used 928 in your area?
CarGurus has 40 nationwide 928 listings and the tools to find you a great deal.
Search Porsche 928 Questions
Porsche 928 Experts