need help on how to hook kenwood cd player in 98 dakota

[73_RoadRunner]

i have infinity speakers stock aftermarket cdhanger and stock radio right now i have a kenwood i tryed hookin up buy no sound was coming out but the cdplayer lighted up like it should work
on the stock radio there is the spot for the black harness to plug in and the grey one and there is 1 single wire that plugs on to the radio itself i'm guessing its ground what am i doin wrong i think the truck might have a factory amp on the wiring harness i have power red wired to red constant power yellow wired to yellow it was black grounded am i forgetting something?

[COOP964x4]

You forgot the blue to blue.(amp turn on)