ripping apart cd rom drive

So I'm trying to make a tray in my dash, and I'd like to use the parts from an old CD rom drive to get the tray to open and close. The tray and fabrication isn't the problem, it's the CD rom drive. I took apart the guts so I was left with only the tray, the tray housing/track, the motor and gears, and the circuit boards needed to run it. (Removed all the laser mechanisms) But now when I hit the button, the tray doesn't open, only closes (the gear that runs the tray only spins cookwise), and I'm not sure why it's not opening. Anyone have some experience with these things, or have an idea how else I can get the motor to open and close (Meaning it would turn CW and CCW alternately, and automatically when I hit the button)

try reversing polarity to the motor. thats how a lot of motors work

There may be a limit switch for the 'open' position that you have eliminated.  Without the switch in place it may think that it is already open, therefore not allowing it to open any further.Kevin Pierson