My wife has a 2002 Lancer that is blowing cold air on the far most left (driver's side) vent but the air gets progressively warmer at each vent going to the passenger side with the far most passenger side vent basically blowing warm air. It does not have dual zone climate control, just the basic hvac controls. If I switch from cold to hot using the controls, just touch will turn all vents to normal heat. I presume this is a blend issue. Any help is appreciated.