finished system,but need help

hi all,i finally finished putting together my audio system.well i thought i did.i fired the car up after it had been sitting for almost two months now.it sounded pretty good.the only problem being i could only get the front speakers working.first ill list my setup,than list the problems/questions

clarion db625mp head unit

infinity kappa perfect 5.1 components

infinity 652i coaxials

audiocontrol 3xs crossover

zapco studio 100,150 and competition 2z50 amp

jl audio wo12" sub

  first off on my audiocontrol crossover since my front components came with passive crossovers i decided to use them instead of the 3xs.so i didnt use the front rca input on the 3xs.i only added the rear input to the crossover.should this matter?should i just run an rca line from the headunit to the front input of the crossover?the reason i ask this is because i have my studio 150 wired to my sub.the 150 powers up but im not getting anything from it.i have the sub output from my crossover to the sub amp.im wondering if the crossover isnt working because of what i mentioned earlier about not using the front rca inputs?thats one thing id like to know if i should do or just leave it alone.

  the other problem i have is my studio 100 amp is wired with my rear coaxial speakers.the amp doesnt even power up so i dont know what the deal with it is.does this mean the amp is dead or ...?is there a way i can test the amp without having it in the car?i just wanna make sure its working first.if not ill just get another one,but it cost me a bunch so id like to keep it if possible.

  i forgot to mention that i have the three amp turnons,crossover and two fans hooked up to a relay.i dont know if this matters but i thought id mention it.

  i know this is alot of information but if anyone can help me id really appreciate it.thanks alot