Having a problem with the heater blowing cold air while its moving.
I have a 2007 Pontiac Grand Prix and while it idles and i turn on the heater it works fine,
but as soon as i start moving, it starts blowing cold air. I changed the thermostat, it has
coolant, the hoses get hot and i even change the climate control module and still
nothing. Could anyone help figure out what this could be?