I have 2 12" kicker subs at 600peak/300RMS with a 460peak/300RMS amp. That's all hooked up straight to the battery. The battery and alternator are factory. The door speakers and rear 6x9's aren't on an amp. So the only thing stressing for the car is the amp and subs. This is in a 2000 olds alero. This system has been in for 2 weeks, the other day I could tell the bass wasn't hitting as hard as normal. The green power light on the amp was on, everything was working but right before the bass would hit the light would start blinking. Obviously it's not getting enough power. Do I need a new battery, alternator, what? I mean, it worked fine until just the other day and its a pretty low-watt system compared to some.
Your system shoudl really have no bearing on the cars charging system. Question, are other or any accessories on the car malfunctioning(Ie: memory on radio not working, or power windows reacting slower or with less power, etc. .? Or, just the amp issue ?
At this point, Id reccomentd to get a DVOM (even a cheap on will work), and see if you are loosing Voltage at the amp. A new batt or alternator .. .. . kinda hard to tell. Sounds to me like there is deff an issue. I think the most imp thing would be to see if you have adequate voltage to the amp. From there, it can be determined more accurately. If the batt was low on voltage adn could not power the amp, you would find yourself haveing trouble starting your car and with other accessories. Under those circumstance, the Alt would catch the slack (except with starting the car) and things would be fine. So, from the desctription above, my first thoguth would be the amp or the electical line from the amp to the batt. Maybe bad conn or something . ... . so give the DVOM a try. It seems most benificail to know what the problem is, by finding out wht it may not be.
Nothing else is happening. All the lights are fine, the CD player is fine, the car starts right up like normal every time. It's just the amp as far as I know. I'll have everything checked tomorrow. Because, I would think that if the system was too much for the car to handle, this all would've happened the day we installed it, not 12 days later.