I have a 97 Jeep Wrangler that will not blow heat in the jeep. The core is not leaking and its not clogged. Why cant I get heat?

#1 a thermostat must be in the system for the coolant to get hot enough to heat the vehicle. #2 check to see if the coolant is flowing through the core by feeling to see if the 2 hoses are hot, if not look for a valve inline on one of the hoses it is rusted shut. If they are both hot then the air mix door in the heater is stuck on vent or a/c and wont let the heat through the door can be opened manually by moving the lever on the heater under the dash