All modern cars make use of the AC to clear a foggy windshield. If your AC is not cold, then get used to a fogged up window.
The cabin temp sensor is right next to the computer control knob on the dash, the one with the little grill. In order to get it out, you have to remove the radio and the ECC panel. The ECC is a little stubborn but comes straight out. Then reach around to the back side of the sensor and grab it at the front (there are 2 plastic tabs, 6 and 12 o'clock) press in the tabs and carefully remove it from the dash.
Becareful with the small metal probe sticking out the front, it cannot be bent. Clean the little fan with a pipe cleaner or toothpick. Replace the temp sensor, it is seldom bad.

Another trick to clear the windshield: crack the driver's window about 1/4 inch while driving.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)