Audio Systems: subwoofer, rca inputs, car amp

Question
i have an arc audio arc 10-d2 10" sub arc 4150-cxlr amp...i have sound from the speakers and base from the speakers but i have no sound from the woofer...no crackle so i know its not blown and all connections are good( i think) i can adjust the bass on the speakers from the stereo  

Answer
You should test the woofer first. Unhook it's leads from the amp, and tap across a 1.5 volt battery. Use a "AAA" or "AA" battery. The woofer should thump and move outwards if you have the polarity correct. Once that test is done, move on to the amp. If you have a portable signal source like an ipod or walkman, get an adaptor to run from the headphone output to the RCA inputs on the amp. Hook up a plain speaker to the car amp out puts (one at a time) for testing, any old 8 ohm home speaker will do. If this all works, try switching the rca leads at the deck, perhaps you just have not turned on the subwoofer output option, if your deck has that.