Sony xplod head unit doesnt power front speakers?

I got a sony explod radio with the ipod cord, everything is great about it, but the front speakers don't work (all factory speakers) i hooked the radio up today.. and i used to a electric tester, and there is no power going from the head unit to the speakers? i was wondering if there is like a setting or something to change, to power all 4 of my speakers, thanks