cd player installation

when installing a cd player in my 1986 f150 i get no power to it. the wiring is connected correctly, red, black and yellow. i even connected a cassette player and the cd player at the same time.....the cassette player runs, the cd payer doesnt. at first i thought the player was bad but i've tried 3 of them. what am i doing wrong?

Here's is what I would do. Run complete new wiring. Take all the old radio wires out, and run brand new ones, then instead of running throught the fuse box, run a new fuse box just for the cd player. If that doesn't work have a pro run it.