Everytime it is raining or muggy my windshield starts fogging up and in order to get rid of it I need to turn on the defroster. When I do this the airconditioning comes on and clears it up. First great that it is fixed but why does the defroster not put our heat. I cant seem to figure out how to change that to heat.

I am also not sure if it is because of a leak in the heater core or a broken seal in the windshield.

Any home remedies anyone would like to suggest.

 

Hi Have had the same problem. - condensation cleared up when defrost was out on. Off side foot wells full of water.under the carpet so worth a check. I found out that water was coming out of the vent under the drivers seat when heater blower is high and set to "feet". When set to body or face no water coming out.Volvo have said that it is due to water getting through the windscreen seal and running down the inside of the car. If you push the screen from the inside around the edge you might see if it moves - if it is the same problem