alpine type x wont work?

Hey guys.. i just picked up a sub/amp combo from a pawn shop back home for my buddy.. I know the guy who owns it and who sold it to me so im sure its not blown or anything.. Its in a custom alpine box and has an alpine 1000 watt mono block amp.. We wired his truck (which took a long time but did get it done and looks decent).. then we start hooking everything up.. the amp powers on but the sub doesn't hit or anything.. played with the deck (which I know very well since i used it for a year b4 selling it to him).. and still nothing form teh sub.. We take the box apart and see that there are 4 wires comming down form the sub to teh terminals on the outside (though there are only 2 terminals and 2 like notches (may be screws?).. tried it again.. nothing.. Then i pull my kicker L7 setup outta my car and run it off his amp and turn on teh music and it starts pounding.. So im woundering if anyone has any ideas of how i can get it working or what needs to be done.. Im not an expert at stereo systems but have done a bunch and never ran into a problem like this.. Thanks and let me know!!

honestly its probably blown.  The dude you bought it from may just have assumed it worked because it wasn't visibly blown (i.e. no tears in the surround, cracks in the cone etc.) Even if it's wired up improperly it should still work to some extent, it just won't sound very good.  I'd recommend either buying a multimeter or taking the sub to a stereo shop and having it tested.  If it doesn't test for continuity or the impedance (ohms) is all over the place when you test instead then its blown.