I have a 1997 Chrysler Town & Country with a two heating issue. The vents on the passenger side only blow cold air when the heat is on. I can hear a damper motor running but cold air comes out.

The second issue is that when there are extreme cold temps (I live in Chicago it 2 degrees today) the heat never really get hot enough. If anyone has a suggestion please let me know.

I suspect the cooling system is at fault.

The heater core may be partially plugged or perhaps the t-stat is stuck open.

Are both heater hoses hot to the touch when the engine is up to normal operating temp?

I replaced the t-stat no luck I will look into the heater core.