I have noticed that my fan speed never runs under two bars while in Auto mode in my SC430. In the LS430 the fan speed will go down to one bar when it has reached desired temperature. I am wondering if this is a programmable or adjustable setting that can be changed in the SC, or if they all behave in a similar fashion, or if my Auto HVAC control is not working correctly. Note that I can manually reduce the fan speed (using the fan speed button) to one bar but then the Auto mode turns off, and if I turn it back on, the fan speed goes to two bars as its lowest setting. It does change to higher fan speeds as needed but never runs below two bars in Auto mode.

 

You might try to clean the smaller sensor vent on both the passenger and drivers side foot wells. I believe they are near midline of the car and look like small 1inchx1inch plastic vents. I believe they house sensors for the thermostat and if they are clogged the car will never know when you've reached target temp and continue to run air speed at higher than expected speed. This is my guess. I'm sure someone might have a more solid answer, but it's worth a try.

 

Thanks I'll give that a try. I am also looking for confirmation from SC430 owners that their HVAC system on auto will run at the 1 bar (lowest) fan speed in Auto mode.

 

I think that mine does the same thing (lowest is on 2 bars) but I thought that I remembered it going down to one. Then again, I don't much trust my memory any more.

 

Mine will only go to one in heat mode in the winter. In AC it always stays at two bars or higher.

 

Thanks for the info at least I know it is not something unique to my car. It does not really bother me but the car's AC is so good that my wife who gets cold super easy would prefer that the fan run at lowest speed once AC temp has reached target setting. .

 

Yesterday, I noticed it down to one bar but it was in the split mode of blowing on the feet and from the dash (I think that means it is blowing warm air on the feet and cooled air through the dash).

 

Just noticed a day or two ago that it was on cool only (no feet air) and at 1 bar. So the temperature range for the a/c unit must be really small for it to set on one bar. Once it leaves that range, it bumps it up.

 

We noticed today very early in the morning and cloudy with zero sun the air was on and set to Auto and fan speed did indeed go down to one bar. Have not seen it very often where we live (hot and sunny a lot) but I agree that the fan speed on Auto does go down to one bar under certain pretty narrow conditions as when load on AC is very light, cabin temp is close to AC set temp and cabin sensors are not getting any sun.

 

Why bother with the auto? I just leave it in manual, set temperature to 70 or 65 if it's really hot, and fan speed at one bar. Comfy enough.