One day my sub just gave out. I checked all the connections and fuses and they were fine. My amp and cap is turned on but my sub isn't getting any signal. Could it be my hi/lo converter?

 

Did you check inside the subwoofer box?

 

Get rid of the cap.

Your amp is turning on but is it putting out power? Meter the terminals.

 

why get rid of the cap?

could it be that my rca cable got damaged inside

 

meter the terminals to see if it's putting out anything.

 

Capacitors are a bandaid for a system. They work in theory, but in real life when used in a system, do more harm than good.

Instead of using a cap, upgrade your power/ground for the amp, upgrade the big3, and if you're really feeling crazy, upgrade some grounding.

RCA cable where? From your HU to the amp?

Only way to check anything is with a meter.....