my 2004 Blazer always puts out warm/hot air with fan only once its warmed up, even thought the heater control is on cold. On a long trip, mild day with no a/c on, its annoying, hot feet with fan off! Dealer says its just engine compartment heat. I think it has something to do with the heater control valve being on the "water exit side" of the heater core. If this is typical, it tells me one thing. If no one else is experiencing this, then I have a real problem. Please advise.

 

Its most likely a stuck damper Ive seen numerous post about this issue.

 

I have the same problem, I would love to have some info on fixing it!I had to buy a dash mount fan to keep from cooking in the california heat.