problems with hu and system

i spent all of yesterday connecting wires from my head unit (boss 620ua),and my 400w audiobahn, 2 12" cvr's to my 1999 chevy astro. after i get everything connected i go to play some music to see if it all works, my front left and rear left speakers were the only ones working and there was no power to my subs, so i pull the dash apart again and redo the wiring to the opposite speakers and no sound comes out at all now. i am half tempted to bring my vehicle to a car audio shop, and have them do it.

thanks for all of your time in advance