Defroster not working properly

2002 TOYOTA CAMRY
195,000 MILES • 2.4L • 4 CYL • 2WD • AUTOMATIC
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JEFF HERMAN
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  • 486 POSTS
The inside of my windshield fogs up in the morning and when it rains or is humid out. When I run the defrost it clears the inside but forms water on the outside of the windshield down near the cowl. As soon as I turn it off the fog on the inside comes back.It also looks like moisture or vapor is streaming up on the outside when I run the defrost. It is a vicious cycle and makes it hard to see out the windshield. I checked the heater core for leaks and found none. I also checked the A/C charge and found it to be about 40 lb. It is draining out the hose freely also. I don't really know what this could be from. I don't know if I need to increase the temp of the defrost or not. Any input as always would be greatly appreciated. Thank you for your help.
Jul 14, 2020 at 6:37 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

What you are seeing is likely the result of cold air on the inside of the vehicle defrosting the windshield and warm air on the outside which is causing condensation. I don't know where you are located, but if it is in a hot area, try allowing the defroster to work at a warmer temp. By design, the A/C turns on when the defroster is on. It helps dehumidify the air. If you have no heat blended with the defroster and it is warm and or humid out, that is what will happen.

Let me know the climate you are in and if you are running just defrost without any heat being added.

Joe
Jul 14, 2020 at 8:52 PM
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JEFF HERMAN
  • MEMBER
  • 486 POSTS
I live in Wisconsin and lately it has been fairly warm in the morning. I adjusted the temp of the defrost to 76 and basically the issue disappeared. It seems that this vehicle requires running the defrost much more often then other cars I have had.
Jul 16, 2020 at 7:52 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

Glad to hear you got it figured out. It sounds like it was simply condensation resulting from the temperature differences.

Regardless, please feel free to come back anytime you need help with something or have other questions.

Take good care of yourself.

Joe
Jul 16, 2020 at 8:28 PM