I have a 2000 Jeep Cherokee and the defrost won't blow warm air. It seems to work coming out of the vents ok but when I turn it to defrost, it stays warm for a bit but them after about a few minutes it gets cold. It wouldn't just be a thermostat issue would it? Usually if it is, then it won't blow any warm air out at all. I also noticed that when I first turn on my heater it doesn't always start up right away. I usually have to turn it off and on or mess with the temp ****. Could it be a blend door issue or something??? Please help. I am a single poor father with a little one so I have to have a proper working heater with winter coming up and can't afford to take it in and have it fixed.

 

Prob blocked heater core

 

If it were a blocked heater core it wouldn't be warm ever.

 

Yes, it can't be the heater core or it wouldn't help at all? Any other ideas?