2005 Chevy Equinox heat air problem

My 05 equinox heat/air was blowing perfect, and then slowly started to stop, coming on sometimes when I would turn the middle knob, until stopping completely. We replaced the resistor, but that did not fix it.

Answer: If you mean the fan is blowing fine, but the air temperature looses heat, then this is not a blower resistor problem.

You may have a low coolant problem.

A leaking water pump or bypass manifold gaskets.

Possible broken temperature door in dash.

See this link for Chevy Equinox temperature door pictures.