Power cap has power amp protect light is on ?

If there is a protection light then you have a bad power or ground connection. First thing I recommend you do is to get a regular test light with a ground alligator clip and test for a ground on your power cable. The way to do this is to place the alligator clip to either your amp turn on wire which is the small blue wire coming from your radio to turn the amp on or another powered wire and place the tip of the test light to the main power cable that powers the amp or the Capacitor and if your test light lights up then you have to trace the power cable from amp back to battery + terminal and see where the power cable is pinched or making a ground contact also check your blue amp turn on wire and see if it has a ground to it. If all this checks out then check your cars battery terminals, make sure they are not loose, corroded, rusty or damaged check fuses or take out amps fuses and reinsert to see if it resets, check all ground connections on amp and cap,if none of this works for you then you might have a defective cap or amp.

Good luck.