kitra

My 2014 GS 350 steams up if I don't keep the ventilation system set for A/C all the time. Even at that, I come out in the morning to leave for work and the windows and sunroof glass are often dripping wet. My other cars are dry and windows are clear. I use the HVAC ECO mode on my other vehicles with nary a problem with condensation. I have to towel dry the windows down on the GS before I leave for work (inside surface). Once at work parked in a covered garage, I roll the windows down a bit to let it clear/dry out.

Anyone else having this issue?

AL13NV8D3R

I have the same issue as you but as long as I keep my A/C on that never happends. Its alright to keep A/C on year round. What most people still don't understand is that the abbreviation "A/C" means Air CONDITIONING and NOT Air cooling. Air Conditioning really means it conditions the air to keep the humidity at a comfortable level. Thats why you can have A/C ON while your heater is ON and set to 80°+. The air blows out hot but DRY thanks to A/C. It drives me nuts when people think A/C is only for summer and spring.

kitra

I totally understand the reason for running the A/C with the heater or defroster. Just seems odd the car feel so "wet" inside. I've had over 20 cars and never had one with water droplets hanging off the window glass and sunroof. I've had cars without air conditioning so the drying effect wasn't even an option. It's a bummer sitting in the driveway for 10 minutes so it clears enough to drive. Plus the engine heats up very slowly.

bclexus

There must be significant humidity/dampness/moisture already on the inside of the vehicle for it to be dripping wet. Condensation happens when there's a difference between the temperature and moisture levels inside and outside the car. Has the carpeting been cleaned recently? Any damp or wet clothing, boots, umbrella, towels or gear stored inside the vehicle? Maybe a leak?

JDR76

What bclexus said.

You should not have that kind of moisture in there.

kitra

I previously called Lexus and the Service Advisor told me it's almost impossible to find a water leak, if there even is one. So I didn't make an appointment at the time. But I think when the rains come back, I will have them take a look at it. The windshield has been replaced at some time as it's not Lexus stamped. The car is CPO warrantied until 2020 and then I bought an extended $$$$ Lexus warranty through mid 2025. Some zero deductible, unlimited mileage warranty.

bclexus

I see that the front windshield was replaced, and obviously not replaced by Lexus. Does it appear that there is more dampness around the front windshield area? Have you detected any awareness that there may be water leaking inside the car through the cowl or firewall area, which may not be seen or touched?

You should always leave the A/C on so the system will 'condition' the air when the engine is running, regardless whether the temperature is 100° or -20°. The system is very intelligent and has temperature and humidity sensors that make ingenious decisions to make the cabin comfortable, which includes pulling humidity out of the air if necessary and recirculating the cabin air when necessary.

SC300Es

Maybe look under your mats to see if any moisture is coming from the top. On my CX-9 one of the sunroof drain hoses had come loose and it was dumping all the water into my front footwell. It is worth checking.

DP03

Definitely not normal. I"m one of those that doesn't use the AC except when needed for cooling. I've never had condensation in my car, even when its raining or humid outside.'13 AWD.

kitra

Appreciate all the advice. DP03, I use the AC mainly for cooling unless I get into the car wet or after a Gym workout. The other thing it does in when the heater first turns on in the morning, it clouds up the windows first before it starts to clear. A bummer if I'm going down the highway and the windshield clouds up.

SW17LS

You need to leave "A/C" on all the time. Never turn the system off, always leave it on. Part of what it does is to dehumidify the air.

In my experience when people have problems like this its because they're not letting the system do its thing.

DP03

But my point is that some of us leave the AC off a lot of the time and don't have this issue. I haven't had my AC on, except for defrost, in months. No condensation. I think he has something else going on....

bclexus

Here are a few more things to do and consider:

• Make sure the A/C is not only On all the time, but make sure you it is set to 'Auto' so the system can select when it recirculates the cabin air, and when it opens outside air to flow.

• Have you replaced the Cabin Air Filter in the past year? Have you checked the Cabin Air Filter to see if it is clogged up with debris?

• Have you checked to see if the A/C system's condensation line under the vehicle might be clogged?

• Does the heater work well? Is there a slightly sweet or melon smell to the air inside the vehicle?

SW17LS

Once you get any sort of moisture in your cabin though, without the HVAC and AC on you'll never dry it out.

For instance by leaving the HVAC and AC on I never even have to run the defoggers.

spoogenet

I have a rather different take than many prior statements. There's nothing unique about this car that requires turning the AC on all the time. I've had many cars over the years and only used the AC to cool the car, with no moisture issues (mind you, I don't live in Oregon).

If you follow the same usage patterns with your GS as with your other cars, including location(s) you park, how you use the AC, etc. then I'd be looking for what's different about the GS.

Some folks have had issues with leaking trunk seals. Lift up the rear cargo mat and look around the spare tire section, is water accumulating?