Wiring remote tilt/trim control - 50 4stroke efi

[Merc504strk]

I've just installed a 2004 Mercury 50 hp 4 stroke EFI and can't get the tilt/trim button on the remote control to work. I have power to the blue/white and green/white wires at the control end of the harness when I activate the switch. But I connected them to the b/w and g/w wires on the motor end of the wiring harness but it still doesn't activate the tilt/trim motor. What am I missing? Is there something besides these two wires that I need to hook up? The motor starts and runs great and the tilt/trim switch on the motor works fine.