it should do the trick pretty much after 30 sec, maybe you should check the freon. does your AC work?
IMHO, "Defog" uses the A/C to cool the air, extract humidity, then reheat it and make it dryer, so as to absorb the humidity ('fog') on the inside of the windshield. To "Defrost", you must turn off the A/C (which probably turns 'on when you press the front window Defog/defrost button) and this will allow heated air to hit the inside of the windshield, heating the glass so that frost (or ice or snow) melt on the outside. Lexus recommends turning temp to "hi" when defrost is needed, but after a short while it is too much heat in the cabin and I then turn it down to the temp. I want.
what i am saying is the air only blows out of dash vents, air will not blow out of windshield defrost vents
