Any suggestions why rear A/C does not get cold and rear heater does not get warm blowing from vents? Rear blower motor works fine and blows air hard, just no cold air or heated air when operating front and rear controls. Front A/C air and heated air works fine by the way. I did take panel off to get access to blower motor screen and it was clogged with dust and I vaccumed it thoroughly but it made no difference and rear vents still do not blow cold or hot. I know there is a resistor behind the panel but I understand it's function is only to run blower motor and has nothing to do whether vents blow cold or hot air, unless I'm wrong about that. I did also install new front filter behind glove box. Any ideas please where to go from here as I obviously need to dig deeper? Thxs!