My guess is what the other guys mentioned...cable head isn't in the socket. Make sure when you thread the cable thru the hole in the outboard wall of the lever body, the shifter thumb button has dumped the racket to the first click. Otherwise the cable won't thread thru the socket hole in the racket arm...you will just thread the cable up thru the lever body and bypass the mechanism. This is a common mistake...pull the cable all the way out and start over if the cable doesn't move with when you push on the lever behind the brake handle.