Amplifier Pinout?

[Retrodog]

I've got an 03 Z4 with no audio from the stereo. The head unit appears to function normally, but absolutely no sound from the speakers. No hiss, no crackle, no whine.

The system also has an amplifier in the trunk, right behind the battery. I'm guessing one of the following is the problem:

1. Amp is blown
2. Power is not present
3. Switching/sensor voltage is not present
4. Fuse

I can't really see any fuse identified on the card as specifically for the amp so I doubt it's #4. But I'd need a pinout diagram to figure out if it's #2 or #3. Where can I dig that up at?

I guess there's always the off chance that I could just re-seat the connector and that might help. Haven't tried that yet.