Problem with aftermarket stereo?

for those that arent familiar with the problem i've been having, here is my original thread.

http://www.tacomaworld.com/forum/2nd-gen-tacomas/144814-battery-light.html

short version, my battery light is on as soon as i start my truck. after some short driving it will go off. both the battery and alternator have checked out fine at 4 different locations when tested.

so i had a thought. i pulled the power wire from my battery for my amp on saturday. drove the truck all week, no battery light. last after work, i reconnected the power lead for the amp. i checked to see if the amp was lit up or anything, and it wasnt. i didnt drive anywhere for the rest of the night, so i'd say the truck sat for a good 12 hours. i hopped in this morning, as soon as i fired up the truck the battery light came back on. and once again, as soon as i drove about 8 miles the light went off. also, i'd like to add i had the stereo off the whole time.

so i'm not sure if this is possible, maybe the amp is steadily drawing from the battery overnight, and in the morning the battery is low but strong enough to crank the truck. but its so low that the alternator can't put the out put to recharge it and triggers the battery light? thats the only thing i can think of, any thoughts?

here is my stereo set up, its nothing huge. i have the stock radio, a line ouput converter that feeds signal to a kicker amp (i forget the exact model, roughly 120 watts rms), that goes to 2 6.5 speakers and a 8" subwoofer. certainly nothing that a stock alternator couldnt keep up with. i've had 800 watt rms amps hooked up to stock alternators before with no problem.

so sorry for my lonnnnng read. any help is appreciated, in the meantime i will re disconnect my power wire to my amp.