2003 Pontiac Sunfire Amp Install

Hello, I am new here and i am looking for some information on a problem i am having with an install.  I am trying to install an amp and subs in a 2003 Pontiac Sunfire with a monsoon sound system.  I am not replacing the head unit so i am using a speaker level input to rca level input converter.  More specificly the American International Car Stereo Ajustable Output adapter AMI part number LC-502 CL.  I installed it the same way i had on many different installs which is the same way it tells you to on the package.  My problem is that i am not getting any signal through the RCAs to the amp.  Could it be that it cannot convert the monsoon's signal because it has too much power?  The package says it converts 2 to 30 watts into the right signal.  I am assuming the monsoon puts out more than that.  I also have the unit hooked up to the speaker wire leading to the second voice coil on the dvc 6x9s because that was the easiest way to access the wires in this system.  If anyone would have anyinformation on how i can make this stereo work please reply.  Any help will be greatly appreciated.  Also if anyone needs any more info to figure out this problem feel free to ask.    Thank you.

Disconnect those wires for now. I imagine that these are rear speakers. Fade the cd player to the rear. Disconnect the other 6x9" entirely. This should leave you with one speaker running. Disconnect the wires from the 6x9" that you hooked into, does the speaker change in output or not, if this is a component 6x9" and not a dual coil 6x9", you may have tapped into the tweeter leads and yes you will get little or no output. Verify that the wires you tapped into are going to the woofer of the 6x9".Top Secret, I can tell you but then my wife will kill me.

Thank you very much, I will try that in a little while when i can get the car over here again.  Another thought that i had was that if it was factory amplified it would probably have a factory crossover and if my loc is connected after the crossover then the frequencies that would be used by the amp's lpf would be low enough to have been cut off by the monsoon's crossover.  This theory goes right along with yours.  This would also explain why the woofers would play the highs if i switched the amps crossover was switched to hpf instead of lpf.  Thank you very much for your advice and please keep up with my posts to see if they work now and if not maybe you will see a different problem.  Thank you again for your advice it has helped me very much.