Tried searching. My 99 ram V10 will only blow Luke warm air. Sick of being frickin cold. Turn temp dial to 1/3 or 1/2 and it quits getting warmer. Is it the temp control unit on dash? A blend door not moving? Or engine not warm enough? Engine temp sits between 130 and 210. Right in the middle, sometimes just a hair less (hard cold headwind) I've felt heater core hoses and one is pretty much too hot to keep hand on while other is just hot. The other weird thing. The lower the blower speed the warmer the air. Full speed and it pretty much wont defrost windows. Please help.

 

I'd flush the heater core.