Try a different exercise, like pullups, bent barbell row, one arm dumbell row... I seldom do cable rows for just that reason, my arms tire before my back, but yes if you use less weight and really concentrate on your lats those exercises can be good also, but I would stick with more basic barbell exercises as your main lat regemin. Just use those other exercises for an occasional change up, or after the basic exercises have already tired your lats some.