2000 S10 Heater problem

[Aldon73]

My father-in-law has a 2000 S10 that the heater doesn't blow hot air in defrost, in floor mode or combo. It only barely blows warm air in upper body mode. The engine is running normal temperature. Is it a blend door actuator problem?  Or a different actuator problem?

[txab]

Have you flushed the heater core? You may not be getting much heat off it. Check the temp of both hoses. But a blend door can be the problem as well. I'm not familiar with the S10s after about '90

[Aldon73]

Will do, thanks