I know this is somewhat late of a reply, but my control unit works the same way. It has since the car was new. If you are put in recirculate mode it kicks the A/C compressor on. Regardless of whether the A/C button is on or off. Samethin when you put in on defrost. The A/C compressor turns on. Kinda don't like this thing doing the thinking for me. Tried the cleaning thing...guess I will see how it goes. Haven't installed the unit back in yet though...still sitting here on the desk.