My 94 3.0 defrost does not work that well. Heat works fine, ac works fine, but the all the windows fog up and the defrost will clear the bottom of the windshield about 4-6'' from the bottom up. Any ideas how to fix this??

 

Mine does the same thing. Hope to hear some way to improve it.

 

Same here. I usually get everything clear from about 5" from the top and then there may be a big spot right in my line of sight

In the winter time, I'll start my truck and leave it until it's warmed up, making sure the blower is off and set to recirculate the air in the cab, instead of letting air from the outside in. The when it's warm and I leave, I'll turn the blower on the medium setting and it usually never fogs up. If I don't do exactly that, it'll always fog up like crazy.

 

I need to write this down! lol

 

As a rule it's best to have the Blend Control set to Outside Air not Recirculated Air.
That way you don't get your humidity fogging the windows.

If it's warm enough you can use the A/C to clear the windows.

 

Ok. Good to know!

 

What works for me when rainy/snowy:
- Set the slider to defrost
- Turn the A/C on (to remove the moisture from the air that causes the fogging)
- Set to recirculate (so you're not pulling in any extra moisture)
- Adjust temp as desired (in heavy snow, I'll set it to cold to keep the warm air from causing extra fogging)
- Set fan speed as desired