It would stall and quit trying to achieve focus on the 7D if I had focused on a near object, moved to focus on a far object and moved back to a nearer object. I took it back and tried 2 more copies of the lens but all had the same issue. That night after trying to solve it by carefully looking at the 7D setup, I realized that Custom Function III Option 4 was set to stop the lens drive if focus couldn't be achieved. I reset this to "1" and then went back to my camera dealer to...Show more →
No, if you read all the posts on the problem, you will see that it has nothing to do with "focus search".
On a 7D with the lens in the 500-600mm range, the lens will not change focus in AI Servo when focused on a far object and moved back to a nearer object.
It will not change focus, regardless of "focus search', focus-limiter, or a poor contrast subject. If yours does, you are lucky.