Intrepid Defroster fogging

I have a 01 dodge intrepid R/T it is the 3.5 liter engine. I have recently had many issues with my windows fogging. I have cleaned them so that is not the issue. Here is what it does. I will be in the car driving down the road. It will be warm in the car and the defroster will have been running the whole time and all of a sudden the windows fog. It gets so bad to the point i can not see out the window and almost have to stop and wait for it to defog. I also know that the A/C was not working great this summer. Could it be the Compressor? I have tried turning off the defroster and putting it on heat in the car and opening the windows and it slowly goes away. Also i can smell the humidity in the car when the defroster is on. I am unsure what part that i need to replace. The heat works great so i would not assume the heater coil, but who knows.

Any help will be great.

Do you have the vent set to re-circulate? If so that is the problem. Turn it to vent. The other problem could be a leak in the heater box. If that were they problem you are or will be seeing a drop in the coolant level.

Does the air smell musty and sweet, like maple syrup? If so, your heater core is leaking. If the A/C wasn’t working, it would take a little longer to defog the windows, but would not fog them up like that.

I think on these cars when you select defrost that it automatically turns off the recirculate function unless you specifically reselect it. On my older Mopar (94) it will not even let you select recirculate when using defrost.

I have not noticed any smell of coolant, also i have not noticed a lose in fluid. I will check that when i get a chance and update you. Also it is not possible to recirculate when the car is set to defrost. recirculate is only for high speed and quick cool A/C.

Defrost relies on the AC compressor to remove moisture from the air. If you didn’t have AC in the summer then you don’t have real Defrost in the winter.

I also checked my coolant level and it was in fact low. I will refill tonight and see how the defrost performance is. Now if the refill takes care of it will that just be a heater coil or will my compressor still be bad?

If You’re Lucky, It Will Be A Heater Core, Radiator, Hose, Etcetera, Unlucky And It’ll Be An Internal Or External Engine Leak.

Pull up your mats and see if the floor has coolant on it.


Many Cars Are Designed To Not Run The A/C In Defrost Mode Below About 40F.


I have not seen coolant on the floor at all.