alero powered sub install

I am trying to install a powered sub in a 2001 Olds Alero. 12V power and ground are OK, and the unit works in autosense mode (except it never turns off: I am trying to put in a remote on line). I tapped into a purple wire that is next to the 12V always-on wire (verified with my voltmeter) which has the following voltage profile:

Key not in ignition: ~0.35V
Key in ignition, turned to "on" position: brief surge to 3V, then back to about 0.35V

I took these measurements at the amp and at the head unit plug (with the head unit out) and they are the same at both places. The amp's power LED briefly glows solid red when the key is turned to the on position, then quickly begins to flutter sporadically. The sub never puts out any sound.

If I turn the selector to tell the amp to ignore the remote on signal and turn on when there is signal on the speaker lines, it works fine.

Does anyone have a wiring diagram? The plug that fits in the back has 2 rows of 12 pins. Each row is lettered A or B and each pin is numbered.

Thanks,

Ben

I ran into a system that had the same pin out harness ( 2000 Pontiac Montana ) and the wiring harness that I received had a wire for 12 volt ignitionon it ( 2B ) . If this wire on your harness ( 2B ) tests 12 volts with the ignition on and zero with the ignition off, then run a wire attached to this 2B wire to the remote turn on lead of the amp.

I'm having trouble finding the "ingnition wire" on an Alero with the Monsoon Sound system to wire in an RF modulated Alpine Changer. 

What colour was "2b" ?

Doug