agc

Hey guys, I notice something yesterday about my climate control. Here is the sequence of events (I have a 2000 LS400)

1. Turn on car (climate control is currently off
2. Turn on the climate control, by selecting AUTO
3. Turn up the temperature all the way to HOT, notice that the AC light is ON
4. Turn OFF climate control system
5. Turn ON climate control system, with the temperature set all the way up to HOT, notice that the AC light was still ON.

My question is why is the AC light ON even when the temperature is set all the way up to HOT

Thanks all
AGC

ozbear

Running the A/C compressor has the effect of drying the incoming air. When the temp is set to hot it would be a reasonable assumption that the outside air has some degree of moisture in it which would fog up the glass. By using the A/C to dry the air this is avoided. You should be able to still bypass the A/C and still run warm air but in a climate control system the "default" setting is with the compressor on. Hope this makes sense.

agc

Thanks guys, I just wondered whether that was normal operations. In my other car (Honda) when you turn up the temp the AC does not come on. It only comes on when you do one of the following.

1. Turn on front window defrost
2. Lower the temp all the way down to 60 degrees (cold)

GRAND_LS 4

iTrader: (2)

The LS isn’t a Honda... Jk

But seriously, I found that I get rid of fog much faster with the A/C on, especially in humid Florida weather.

sactogs400

That sucks, with these gas prices, shouldn't we get better milage if the A/C is off.

GRAND_LS 4

iTrader: (2)

You do.....

sactogs400

LOL, so you pay more $$ to use the auto climate control.

Guess $$ is no object when you own the Lexus.

GRAND_LS 4

iTrader: (2)

I don’t get what you mean.

When the A/C light is on, it means the compressor is operating, thus using up about 20-30Hp (It’s different in every car).

So it really doesn’t make a difference weather you use Auto or not. However, if you’re talking about WINTER driving, then I don’t even see why some people use the AUTO feature. Just click the fan speed, and set the temperature to your liking. I NEVER ever use AUTO, weather its winter, or summer, or ever, because it blasts air at 500 million miles per hour, UNTIL the car cools down. I prefer to be in control, and adjust the fan speed myself.

So if you dont need the air compressor, just start the A/C, and then press the AC button to turn off the compressor (light will go off).