For both your heater and air conditioning not to work means you either broke a belt or the belt is loose. Overheating would also be caused by this, because your water pump is driven by the same belt. Do not drive it until you get it fixed, you'll kill that engine by overheating it.
Thermostat and/or heater core may be defective
YesYes
I am pretty sure that's the air conditioning button, it should be right up there on the heater/ac controls.
There is a fuse that protects the HVAC (Heating, Ventilation, Air Conditioning) blower motor circuit.
no
Yes. There could be several reasons for engine to overheat.
Mine Does
There are a few reasons why a 1992 Jeep Wrangler 2.4 liter would overheat. Some of the reasons are low antifreeze levels, radiator leaks, or fan malfunction.
The 1988 Jeep Cherokee air conditioning low pressure port is located on the air conditioning compressor. The low pressure port will be on the right hand side of the compressor.
It was an option
your air conditioning
I also have a 2000 jeep wrangler. This year has a problem with the heater core plugging up. You can either try to flush it out, or just replace the heater core.