To answer my own question, I measured the voltage on the "Sensitivity Control" pin without the factory radio connected but with the amp powered up. It said 5v. I connected that pin to +12v and GND, first through a resistor then a straight connection, and it didn't have any affect on the ga...

Apparently some people are connecting the speaker outputs of their new head unit to the M&T amp and getting too much amplification. Has anybody experimented with the "Sensitivity Control" wire (pin B6 in the dash harness)? Does anyone have the official spec on how that wire functions? ...