Excessive moisture in the cab

Turn on your ac and it won't do that

 

I try to get by setting vent mode to heat/defog first, before turning AC on. This will actually run AC off and on, not as aggressively as pushing the AC button though (monitoring AC Watts with an XGauge on ScanGuage).

Step 2 is to crack the two front windows slightly, and this often will be enough.

Step 3 is to hit the front windshield defog button, just for 30 seconds or so, then off.

If all this fails, I'll cave and hit AC, and try to remember to turn it off, roll windows down slightly, a mile or so before destination, to give the moisture that's accumulated on the AC evaporator time to burn off.

Oh, and breath through your nose: less windshield fogging, lol.

 

I heard someone found a bunch of silica gel packets and put it in their car to help reduce the inside moisture though I would imagine those would moisten up quickly and would have to be reheated to remove the moisture.

Another story was where someone put chalk sticks inside their car which apparently helps. Just be prepared to tell your passengers the story if they are wondering why you might be playing with chalk though.

 

Have you figured out the difference, if any, between defog mode and pressing the front defog button? I haven't. I normally use the former strategy, which is effective, and may(??) rely less on the compressor.

 

Setting mode to Heat/Defog is definitely more conservative. I'll use the front defog button only for a minute or two, to accelerate windshield defog. It seems to be running the compressor at higher wattage, and more.

 

fill nylon stockings with kitty litter

 

I would suggest you do something very simple. On the passenger side of your Prius, there is a drain plug, which drains water condensation from the windshield area out the bottom of the Prius. This tube can get plugged. Its gross, but if you suck on the tube it will start to flow again, and drain as it should. Went its pugged the symptoms you've described will happen, and the carpet on the driver side will be soaked, thus increasing the humidity in the car. Find the drain tube, and suck on it to get in flowing, then stick it back in its exit hole. Rinse out your mouth, dry the carpet, and problem solved. The dealer will charge you a labor fee to do the same thing of whatever their service rate is. If they want your business, they'll just show you how to fix the problem, and you'll be good to go. This has happened on our 04 and 2012 Prius's. Adrian