My mechanic changed the starter and wiring, but after 1 month, the same problem is back. I've noticed it only happened when the AC was just turned off before stopping the engine. It didn't happen if I turn off the AC a few minutes before turning off the engine or didn't use the AC at all.

 

This is a start/non-start issue and your post relates to conditions when the engine starts or not?

Did the mechanic check out the AC compressor for problems?