[Alex 67]

I have recently purchased a 67 Irish Green 912 and am considering a radio upgrade. I have the original but there is an old Sanyo in the dash there were no cuts made to make it fit. I am concerned with putting a newer system in the car and how to hook it up I went underneath to take a look and found a red wire with an inline fuse ( not sure where it goes)and just the speaker wires connected there is a black wire which I think is the ground but it is not connected and when I did connect it it blew the inline fuse. When I turn the car off and the radio is still in the on position the radio still plays. I will mount the new system under the dash or build a holder for it so not to make any modifications. Has anyone upgraded their system and what can I do.