After using the A/C all summer I turned the system to defrost to get some steam off the windshield. It will only blow cold air even though I have the temp **** turned all the way up. Also when I turn the selection switch to floor air it still blows only thru the defrost. When I set it to panel it blows where it should but still cold. The radiator is full and the temp guage shows it is getting warm properly. However only one of the heater hoses is warm going into the heater core. Right now it isn't a problem but I will need some heat before too long.

Any help or suggestions are appreciated. Thanks

 

I had the same problem with my 99 Blazer and the dern heater core was stopped up with all kinds of crap. I flushed it back and forth a couple times and the water ran clear. Lots of heat after that.

 

Thanks for this information, I will certainly be giving that a try. Flushed out the heater core this morning and now i can get lots of hot air. Now I can work on the no air coming out on floor, but at least I can manage to beat the cold.

Thanks,

Jim