I know a capacitor has a lil bit of power left, but when the key is taken out of the ignition(turned off obviously) should the capacitor stay on for a few seconds, or turn off as soon as the key is in the off position?

BTW, the capacitor is what holds up power for the amp to keep it from draining..its plugged directly into the battery.

 

Charge has to dissipate.

 

Lil bit??? no those actually hold quite a charge...

and yea, they take a while to discharge...

 

Well yea, they do, its just that when the 1200 watt amp hits it drains it pretty fast...you know what I mean

 

Cap will stay charged as long as it is attached to the battery. Your ignition doesn't have any affect on the cap.

 

shouldnt this be in the car audio section lol......

yea my caps do the same thing....it takes them a minute or two to decide to finally go off.....if theres any kind of electrical surge in the car ie: alarm goes of or remote keyles opens door...my caps come on then go off a minute later