[kkuz]

I always use AC to keep windows transparent on wet days. I recently found that AC doesn't help as I had expected. It does the job but every 5-10 minutes the fog suddenly comes on windshield and disappears after another 1-2 minutes. The cabin filter is new, AC works normally except humidity removal. Any suggestions?

 

[next2pool]

It's possible your compressor is cycling based on temperature and humidity of the ambient air. Another possibility is a clogged drain in the evaporator housing.

 

[kkuz]

Thanks. I think compressor doesn't turn on while outside temperature is below 50F (winter time). Nevertheless turning AC on in other car is very effective in that case...

 

[like2drive]

I have seen that the AC light turns off when temp is below 41 or 40F. However, the only time I have seen little fogging is when I pressed the re-circulation button and forgot to press the auto setting back on.

 

[next2pool]

Thanks. I think compressor doesn't turn on while outside temperature is below 50F (winter time). Nevertheless turning AC on in other car is very effective in that case...

I think the compressor will run down into the high 30's if it is needed. However, it will cycle at any temperature even into the 80's if the cooling capacity isn't needed. Also, you should avoid using recirc in humid and cool tempersatures. In fact the system normally disables recirc mode if the defrost is on. If you continue to have fogging problems you may have a slight water leak into the interior that you aren't aware of.

 

[C&C]

Depending on atmospheric conditions, with the a/c on, it may cool your windshield and 'cause' condensation (to form). Time to hit the defrost and let the air 'blow' onto the windshield (and as the car warms) blow warm air. After the defrost catches up (to clear the windshield), then turn it off (with the a/c taking over the de-humidification duties.

 

[kkuz]

Yes. It works that way, thanks. However, in Hyundai I do not need to do this, just keep AC on and never have fog...

 

[lord_galathon]

Yes. It works that way, thanks. However, in Hyundai I do not need to do this, just keep AC on and never have fog...

Maybe your Hyundai's floor is dry vs wet in the Cadillac. That carpeting in the CTS is much more plush than the velours they use in Hyundais...

 

[kkuz]

Good point, but I use carpets from the same factory and material as I have in Hyundai. It looks like fog is coming very fast from air grille, and then disappears in seconds...

 

[MoistCabbage]

It certainly does sound like its being caused by the A/C not running continuously.

In my experience, what you use to wash the windows can have an effect on fogging. I've been using Invisible glass for years now. Not only is it an excellent cleaner, but it leaves no residue behind at all and I've had it reduce fogging on several cars I detail for friends and family.

Also, you could always try an anti fog treatment. Rain-X makes one.

 

[tinman]

Invisible Glass is the stuff! Love Stoners!

 

[kkuz]

I will try a cleaner with anti fog function, thanks!

 

[zen]

Possible small leak in the heater coil and some coolant is seeping out into the air stream

 

[lord_galathon]

Possible small leak in the heater coil and some coolant is seeping out into the air stream

I've had that happen before on another car (Suzuki) and the windshield became oily, that was my first clue. Then I got some coolant at my feet, which was my second clue.

Wound up ordering a core from RockAuto and replacing it myself. 8hr job, took apart the whole dash...

 

[kkuz]

Invisible Glass is the stuff! Love Stoners!

After some testing I can only confirm. Yes, Invisible Glass from Stoners is the stuff. Thanks!

 

[tinman]

After some testing I can only confirm. Yes, Invisible Glass from Stoners is the stuff. Thanks!

It IS the schnitzelgruuben!