I made an interesting discovery tonight on my car. The air conditioning pump runs when you have the vent selected to floor only and there is no way to turn it off. WTF? This means that all winter long our air conditioners will be running when the floor heaters are being used. Here is a summary of when it runs:

vents only = AC off (user controlled)
floor only = AC always on (WTF?)
floor + vents = AC off (user controlled)
defroster only = AC always on
defroster + floor = AC always on

Personally, I would prefer to turn the AC on when I want. I don't like the fact that Mazda has decided that if I am running the floor vents only then the AC pump is running. This is wasting a lot of gas for those that run with the floor vent only and don't want the AC.

 

something is not right here

Ok on most cars these days the AC is on with the defroster so that you run the AC in the winter, it defrosts faster this way.

But I noticed the other day that mine doesn't turn on I can turn it off or on when I have it on defrost!

I know I'm not wrong here, as my father in-law said HEY, your AC isn't on on defrost???

I was confused as well, as I thought it had been before.

I also never noticed the AC go on when I have it on feet only.

Oh oh, I hope this is not another problem! Although I like the fact that I won't have the AC on all winter now :D

I'll test it out again tomorrow but I'm pretty certain my AC never turns on by itself.

 

The light will not turn on when you set it to floor only. It will engage the compressor but not turn on the light. A lot of cars do not turn on the AC indicator when you set it to defroster but the compressor engages anyways.

The compressor will cycle on and off when you have the airflow set to floor only and AC turned off. The AC on/off swith does nothing but turn the LED on and off. I hate some of this automatic crap.

 

Ok I tried it this morning, but I couldn't confirm It's cold out.

I agree it does seem like the compressor is on but the AC light isn't, how stupid is that???

When the defroster is on you cannot not pick circulate it must be fresh air only. But yet the AC light doesn't turn on! ????

Man what was mazda smoking on this one, here I am thinking, well I turned the AC off, look the light is off! STUPID!

And I agree, why would I want my feet to be AC'ed?

 

Can't help you guys on why the AC compressor is kicking on when the vents by the feet are selected but I do want to add that all cars have a temp sensor that prevents the compressor from kicking on when it's cold out. Most cars have it set to around 37 degrees F though it could be different on some. This is to prevent the AC compressor from freezing. I'm sure someone will come up with a bypass to circumvent the auto AC on "feature" soon enough. Can't be too hard if the wiring diagram is looked at.

 

I will confirm in my car later today, but I am sure I've had mine on floor w/o the AC on. And you can tell the AC kicks in on defrost and in my experience (we've had a lot of rain here the past week and humidity) it clears the windows quickly.

 

if you think this is bad you should see the climate control system on our Mazda 6 - the AC is ALWAYS ON when the climate control is working! There is no shutting it off without deactivating the climate control.

It turns out Mazda basically is using the AC as a dehumidifier in non-AC conditions.

 

I agree. I know for a fact that the AC runs when feet only is selected. It was humid and my windows kept fogging when I selected feet/vent combo. As soon as I selected feet only, the windows would clear up from the dehumidifying action of the AC. I could also hear the pump cycling on and off.

I would like the AC to turn on and off as indicated by the light. Some other cars (1999 mitsu eclipse for example) run the AC with the indicating light off to dehumidify the air to clear the windows. I hate this.

 

This is stated in the manual on page 6-7...

It says the AC is on even if the ac light is not lit...

Simon.

 

I wonder if this is reflected in some owners MPG numbers without there knowledge ? Compressors are usually a big draw. Just a thought.

 

This is not at all unusual in cars with auto climate control. All Benzes since '92 do this when on auto. You just set the temp and forget it. The system does whatever is needed to maintain the temp set. Wish my 8 had this, but alas, I have to set the temp myself, manually, and this is so hard. BTW, I've had absolutely no problem with my a/c, on or off, up or down. If you don't think it's right, go to the dealer!! It's so simple.