The ac in my car works great on level gorund, but when you up any type of incline it blows hot air out or switches to the deforst and blows hot air out.

http://ricksfreeautorepairadvice.com/car-ac-blows-cold-blows-warm/
Car AC blows cold then blows warm Ricks Free Auto Repair Advice

this is going to sound silly, but check you coolant level... if the level is ok, you will have to check to see that the blend door is operation properly. the blend door is located inside the box on the passenger side of the dash. also, check the switch that lets you go from hot to cold....

Go to Midas,they do great A.C.work,your Freon may have leaked out,they can test for a charge of 19.95..

charge the a/c add a/c dye and ck. for leaks

For this types of problem,i suggest you to check this help links:----Car heater blowing warm, but not hot air?http://schematicsdiagram.blogspot.com/2011/12/car-heater-blowing-warm-but-not-hot-air.html
---------A/C, heater, defroster fan, not working?http://technoanswers.blogspot.in/2012/02/ac-heater-defroster-fan-not-working.html
--------Heater problem?http://technoanswers.blogspot.in/2012/02/heater-problem-on-isuzu-trooper.html
---------Engine Overheats and heater blowing cold?http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html
-----------Heat blows cold on drivers side and hot on passenger side?http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html----------------This will help.Thanks.

Probably broken blend doors if everything else is working, but its just blowing cold air. Do a google search for "Jeep Blend Doors" or "Heater treater" for more info.

since your buddy is a Chrysler tech, he should know that the heater module can be recalibrated with the scan tool or pull the POSITIVE cable off for five mins and put back on restat the car and select all modes, I assume this worked prior to batt replacement, sevice manual helps you do a manual calibration in different modes. GOOD LUCK RDJRP

either the freon charge is about 1/3 low, or the expansion valve needs to be replaced. Freon is getting into the evaporator, but not in great enough volume to cool the air unless it is coming in cool to start with. check your ac charge, and if it is full, then have it emptied, change out the expansion valve, and recharge it

I know from experience that if the coolant is to low ( not just the freon levels in the compresor but the antifreeze/coolant level as well) the AC system will not cool and will blow hot. Check the coolant Antifreeze and freon levels, even with the Coolant being a little low my 1998 Ford E150 Van will blow hot. After you have ruled out of these possibilities and the chance it is the thermostat most likely the problem is what Ford calls the "Flap" it controls the air flow through the vent system when you switch from Heat to AC. When the Flap is working it closes off one systems air flow so as to not interfere with the current climate selection.

working on 4 and 5 speed that the resistor that broken cold air you got to move the selector to see the motor that move the trap hot and cold sometime when the motor was not move to the hot side for a long time its jam the motor on the passager side under dash put to hot and gently tap the motor tanks pierre