first of all, it is south dakota cold. is it natural for cold air to come out of the defrost vent when warm air is coming out the bottom vent and under the seats? it seems that they are offsetting each other. the defrost vent is warm when it is only on, but cold when either in the economy mode and/or air compressor mode. i've read before on the forum it might be the monovalue, but not sure. thanks for any help and happy holidays