Low Coolant? Bad thermostat? Heater core plugged or restricted? Heater core airbound? Heater control cable not working?
Leave it turned off.... doh
It is either your water pump or your thermostat
Usually the horn and cruise control go together because of the clock spring. It needs to be replaced and there is a recall for it.
The flap is stuck open that controls when and where the heat goes
The rear air conditioner is a separate system. Dodge did a recall because some of the piping deteriorates and loses its charge. It sounds like you are experiencing something like that.
You need to first check that you do not have any vacuum leaks and then check the a/c / heater door operations, if all are working then its possible that you have a slightly clogged heater core.........
The first thing to have checked is the amount of R134A that the system has and to service it to specifications as the amount is very critical. If that is okay then then system may need to be reprogrammed.
Temperature blend door motor likely defective. Default position is high heat.
It is possible that there may be air in radiator.
Blow up - 1998 was released on: USA: 1998
Check the horn relay
Assuming you want it to blow hot, it could be low on coolant, a stuck open thermostat, a plugged heater core or a faulty temp blend door.