Do you have any inline fuses or a fuse in the deck? If so I would check to see if they are blown. If you're using the stock wiring harness from the car I would check to see if the radio fuse is blown. You said you checked the connection using a multimeter where did you check the connection at? Did you use both the 12v+ and the ground wires or did you ground it to somewhere else? You could have a ground problem as well. Everything sounds like it's wired correctly so you have a bad spot somewhere.