big 3, battery, alternator still dimming

did you charge the capacitor before installing it? im not sure if all caps need to be charged but all of my fosgate ones had to. that is strange to be dimming the lights with under 500 rms. i had a system in my old car that was running 800 rms with stock battery, stock alternator, and a 1 farad cadence cap and the lights would never dim on it even at high volume and bass boost all the way up.