1997 Toyota Previa Owners Manual - Page 125
1997 Toyota Previa Manual
Page 125 highlights
Defrosting The outside of the windshield For best results, set controls to: Fan speed -Any setting except "OFF" Temperature -Towards WARM (red zone) Air intake -FRESH (outside air) Air flow -WINDSHIELD On models with air conditioning, moving the air flow control lever to this position turns on the air conditioning. This is to clear up the front view more quickly. Moving the air flow control lever to another position turns off the air conditioning. S To heat the vehicle interior while defrosting the windshield, choose floor/ windshield air flow. 119