OP: the left lever on your bike is designed for a road deraileur, not a mountain bike derailleur like the Altus. The amount of cable that it pulls to change the positon of the Altus derailleur is incorrect; you will likely never get proper shifts with that derailleur.
Try to find a single bar end shifter. Microshift make 3x9 bar end shifters for MTB components; you could try to find one for indexed front shifting. Otherwise ask a bike shop mechanic if he has an old bar end shifter that he can set up to change the Altus shifter in friction mode.
Last edited by PDKL45; 12-20-17 at 07:45 AM.