bml320

I have a '98 ML320 with the factory Bose premium audio. I'm considering replacing it with another audio system (Sony CDX-GT310) that has integrated iPod control. I originally thought it would be a straight-forward swap, but now I'm not so sure.

- Some things I've read on the web suggest that the factory system has a separate amp, but I don't see anything in the owner's manual referring to it. Can anyone confirm whether the amp is integrated with the head or separate, or if the speakers have built-in amps? If the amp is separate, where is it located?

- The new system has a 10amp fuse, whereas the factory system has a 3amp fuse. Will I risk burning out wires or other components if I install the new unit and crank it up? If so, can I just "derate" it by replacing the fuse with a 3amp? Does anyone know the max. input power for the factory speakers?

- Can anyone provide a list of the wire colors and purposes? I've identified the speaker wires, and the CD changer wires, but I'm not clear on the others (power, dimmer, ???).

Thanks!