Why won't my sub woofer work?

I currently have a 12inch 1000w PolkAudio sub installed in my car, running off of a mono channel Kicker amp. Have only had the system in my car for barely 6 months, and this morning my sub just randomly wasn't doing anything. I've checked all the connections and everything looks fine, and the amp is fine and working perfectly. I can honestly not see one problem or reason why my sub wouldn't be working, as the rest of my sound system is working fine, without any problems. Can anyone offer any advice that may help me find what the problem is or has anyone been in the same situation before? Thanks heaps in advance for any help with this.