Windshield won't defrost

[nbullock38]

If you are sure that the fog is actually inside (external fog on cold days can be cleared with wipers), and it is not clearing, then you either have non-functional A/C compressor or excessive humidity inside.

Does your AC work well to cool the cabin on hot days??

Try to direct air through windshield vents and manually turn the ac compressor on (there is also a button for that) and see what happens.

Yes, fog is on the inside, AC works great in the summer. I did not have this issue until they took they repaired the cam phaser rattle. Any chance the two are related?

 

[Ellison Brown III]

Is the Recirculate button turned to the OFF position?

 

[Deadman]

Does the air even blow out the defrost vents ?

 

[nbullock38]

Yes. Air blows out of the defrost vents and the recirculate button is off and AC button is on.

 

[Deadman]

If the air is blowing, then you simply have too much moisture in the cabin to dry the glass off. Find out why the car is so damp inside.

 

[BSarchet]

This is just my experience, but my last two Fords seemed to be bad about holding moisture in the cab. I had a Taurus for 7 years, then now an Expy and I started keeping a damp rid pack either under the seat or in the back of the trunk. Seemed to help with humidity in the cab, mostly I was trying to address the vinegar smell these tend to get in the AC system after a number a years. Only in the last week have I had to use my Expy's defrost, but it worked almost immediately. But I noticed the need right after I had to use my umbrella in the rain and then but the wet umbrella in the back.

 

[Deadman]

This is just my experience, but my last two Fords seemed to be bad about holding moisture in the cab. I had a Taurus for 7 years, then now an Expy and I started keeping a damp rid pack either under the seat or in the back of the trunk. Seemed to help with humidity in the cab, mostly I was trying to address the vinegar smell these tend to get in the AC system after a number a years. Only in the last week have I had to use my Expy's defrost, but it worked almost immediately. But I noticed the need right after I had to use my umbrella in the rain and then but the wet umbrella in the back.

exactly, its internal moisture!

 

[GlenS]

I have a similar issue in my 2020 Expedition. When the outside air temperature drops below 29 degrees the car windows and windshield instantly start to fog and the air becomes humid. The inside of the car is dry and the air outside is dry. Could this be caused by the car not switching to fresh air? I have tried using a/c as well as everything else.

 

[Deadman]

I have a similar issue in my 2020 Expedition. When the outside air temperature drops below 29 degrees the car windows and windshield instantly start to fog and the air becomes humid. The inside of the car is dry and the air outside is dry. Could this be caused by the car not switching to fresh air? I have tried using a/c as well as everything else.

Moisture is moisture. If your windows fog inside, then you have moisture in the car. Maybe the sun roof leaks, maybe wet shoes, whatever it is.......

 

[GlenS]

Moisture is moisture. If your windows fog inside, then you have moisture in the car. Maybe the sun roof leaks, maybe wet shoes, whatever it is.......

Why does it only fog at 28 degrees or colder outside temperature? If it was moisture inside one would think that would fog at temps above that.