Car Stereo / Head Unit Problem

Model: 996, Year:2001, Mileage:60000, Type of use:Street use only
I am having several problems with an Alpine Head Unit installed in my 2001 Porsche 996 Coupe.A sound which corresponds with the RPMs of the engine can be heard when the radio is on.A clicking sound can be heard when the radio is on.The OEM radio connector is not in it's original state. Apparently one of the two connectors were removed to accommodate an older Alpine head unit. It seems that the connector which was removed connects to the OEM amp and / or DSP system.There are several wires from the vehicle which have no connection point.I have ordered an OEM wiring harness from Becker audio in an attempt to connect the wires from the vehicle which are loose.One of the things that would help would be a color coded wiring diagram of the OEM radio and DSP system, or possibly some photographs of the wiring and the connection points.