Okay guys, been reading alot on this. I checked for leaks everywhere except under the battery, haven't had time yet. But I don't think its a vacuum leak and heres why. I am not defaulting to defrost. Everyone turn of the switch makes the solenoids move. And here in lies the problem. No issue with defrost to floor modes. Now I looked under the dash and only have two solenoids. One adjusts defrost and the other adjusts floor. I looked real hard and could not find the third solenoid if there is one. (04 Rubicon). when I switched to vents and floor on the knob, I get full force face vents and no floor. I can see floor solenoid close on the way. now from here if I switch left or right (which should be full face vents, ac and non ac. Then solenoids opens half to the floor and I get half and half. its as if the lines are backwards. everything else functions fine as far as hot and cold and max air. Full defrost to full floor works great with nothing out of face vents . but the combo of full face to half and half is working backwards. I hope this makes sense. I appreciate any help.