Wont aswitch off defrost mode for anything, wont switch to vent or heater

I suggest checking the information that corresponds to the manual: 93ZJ_Secc_24 Heating and Air Conditioning

Good luck!!!

You have the exact same problem i did. there's vacuum tubes behind the control panel (if i remember correctly the tube i had was black) and it will most likely be hiding down in your mess of wires as mine was, and you'll either need to photograph the tube and the vacuum connection hub and i'll walk you through what to do with it, or you can buy the haynes jeep manual for your specific year and style and it will be under cooling, heating and air conditioning systems (3-13) if you get the 1993 thru 2004 manual.