99 JXI Convertible Heater Not Working
 

The heater on my 99 JXI will turn on hot but after a few seconds will turn cold. I can turn it off and turn it back on and will do the same thing. Replaced the thermostat and coolant and still nothing. Any ideas?

Check the operation of the blend door. It's a flapper inside the heater plenum that controls temperature by adjusting the mix of hot and cold air coming in.

sounds like a heat core clogged up. Warm engine up feel both the hoses going into the fire wall they need to feel hot where you can not touch them.