Auto Climate Control Question

[DurhamProPhoto]

Ok this is probably a really silly question but
it is 62 degrees outside and the car is cold when
I start it and turn on auto climate control the AC
light is on. If I turn off the AC, the auto control
also turns off. With the AC light on am I not using
more fuel? or is the AC in a stand-by mode?

Cheers,
Robin

 

[P_bouchr]

Yeah good question, i'm wondering the same. My guess is that A/C is on whenever Auto is on. Don't worry if it's colder outside than the selected temp, hot air will come out and A/C is off. Well... I think .

 

[irloyal]

If a tree falls in the woods and nobody sees it does it make a sound?

Which came first the chicken or the egg or Marilyn Chambers?

(enguard)

 

[NYMZ5]

The AC light being on doesn't mean the AC compressor is running, only as needed depending on temp selected as well wether defrost is selected (where the AC will cycle on/off to remove moisture from the cabin).

 

[P_bouchr]

Yeah, but you have to agree they should have lit the A/C led only when the compressor is on...

 

[rodslinger]

Yeah, but you have to agree they should have lit the A/C led only when the compressor is on...

So in the summer time you want to watch it blink on and off as the compressor cycles?

 

[was98strat]

So in the summer time you want to watch it blink on and off as the compressor cycles?

Nope the AC light always stay's on. The climate control is wonderful! I set it when I bought the car 3 months ago and have only ajusted it a few times since!

ant usually only by a degree or two either side of my set temp (21.5) I'll probably adjust it up a couple of degrees for the winter. It does a great job of keeping the car comfortable.

 

[bulwnkl]

The AC light being on doesn't mean the AC compressor is running, only as needed depending on temp selected as well wether defrost is selected (where the AC will cycle on/off to remove moisture from the cabin).

Sorry, not true. Whenever the A/C light is on, the compressor system is running (cycling). ALWAYS. It doesn't make any difference what the outside temperature is. Whenever the Automatic Climate Control (ACC) is on, the A/C system is also on. ALWAYS. It's an idiotic thing to do.

In addition, whenever the system is in manual mode and the air is directed to defrost, defrost/floor combination, or floor only, the A/C system is running (cycling). ALWAYS. EVEN WHEN THE A/C LIGHT IS OFF. This also doesn't depend upon outside temperature. I don't mind the A/C running automatically when I have the control set to defrost, but to have it run when the system is directed to floor only is idiotic.

Both of these idiotic tactics are also wasteful of power and therefore fuel.

 

[was98strat]

Sorry, not true. Whenever the A/C light is on, the compressor system is running (cycling). ALWAYS. It doesn't make any difference what the outside temperature is. Whenever the Automatic Climate Control (ACC) is on, the A/C system is also on. ALWAYS. It's an idiotic thing to do.

In addition, whenever the system is in manual mode and the air is directed to defrost, defrost/floor combination, or floor only, the A/C system is running (cycling). ALWAYS. EVEN WHEN THE A/C LIGHT IS OFF. This also doesn't depend upon outside temperature. I don't mind the A/C running automatically when I have the control set to defrost, but to have it run when the system is directed to floor only is idiotic.

Both of these idiotic tactics are also wasteful of power and therefore fuel.

Are you sure? When I have (on the occasion that I use the moonroof) turned off the climate control. I can clearly here the AC clutch disengage. It only re-engages when I turn the Climate control back on.

 

[Antonio DiMarco]

How do you know?

Sorry, not true. Whenever the A/C light is on, the compressor system is running (cycling). ALWAYS. It doesn't make any difference what the outside temperature is. Whenever the Automatic Climate Control (ACC) is on, the A/C system is also on. ALWAYS. It's an idiotic thing to do.

In addition, whenever the system is in manual mode and the air is directed to defrost, defrost/floor combination, or floor only, the A/C system is running (cycling). ALWAYS. EVEN WHEN THE A/C LIGHT IS OFF. This also doesn't depend upon outside temperature. I don't mind the A/C running automatically when I have the control set to defrost, but to have it run when the system is directed to floor only is idiotic.

Both of these idiotic tactics are also wasteful of power and therefore fuel.

You seem pretty confident with your information. Are you a tech? Every Mazda I've ever had cycles the compressor. You can actually feel it come on via a clutch.

 

[jandree22]

I have no clue myself... but in the past months when this subject was brought up occasionally, I've heard several times what bulwnkl said pretty much word for word.

I agree, kinda dumb, but oh well.

Below are two excerpts from the 2006 Owners Manual...

 

[Wuster]

Yeah my old Mazda3's manual climate controld did something silly like this too. As soon as the position indicator is turned to the floor, defrost/floor, or defort, the a/c comes on. But the a/c light didn't come on.

It was buried in the manual.

 

[bulwnkl]

98strat, I think we are in agreement. I'm saying that when the ACC is on, so is the A/C system. The compressor will continue to cycle, though, if the air is directed to the windshield, windshield/floor, or floor-only. Ambient temperature is not a factor.

Antonio, no, I am not a Mazda tech. I have spent literally hours trying to verify this both on paper and in the real world. I don't have any better paper than what's posted in this thread, but observing the car has been very instructive. This is just how Mazda designed it to work, and I think it's fairly foolish and often unnecessary. Fortunately, our car still handily beats the EPA highway estimate, even in town most of the time, so at least the fuel economy side of it is not bad for us.

 

[jandree22]

Do you guys notice a performance penalty when the A/C is on? In my wife's Solara I can barely notice a hit in performance with the A/C, but my Sunfire became a sick dog when the A/C was on.

 

[was98strat]

Do you guys notice a performance penalty when the A/C is on? In my wife's Solara I can barely notice a hit in performance with the A/C, but my Sunfire became a sick dog when the A/C was on.

The AC clicking on is almost imperceptible. THe only way I can tell it's on is the Click the compressor clutch makes (only really noticable with the windows down in the driveway. BUt I agree with you on the performance concern), my old Dodge Stratus nearly stalled it's self if I turned on the AC at a stop light. My parents Cavalier did the same thing. Just another facet of Japanese engineering!!!

 

[Lazy Glen]

Dodge Stratus nearly stalled it's self if I turned on the AC at a stop light. My parents Cavalier did the same thing. Just another facet of Japanese engineering!!!

On the 95 Protege that we traded in for the Mz5, I called the AC button the turbo boost button. If you wanted to add some power off the line, you just hit the Turbo Boost (turning off the AC) and got a perceptable increase in power.

I haven't tried it in the Mz5, but I haven't needed extra power either.

Lazy Glen

 

[Zoom5Zoom]

On heavy acceleration the Mazda 5 AC will "turn off" with little effect on confort.

 

[Antonio DiMarco]

I think it's more to protect the stupid than anything.

98strat, I think we are in agreement. I'm saying that when the ACC is on, so is the A/C system. The compressor will continue to cycle, though, if the air is directed to the windshield, windshield/floor, or floor-only. Ambient temperature is not a factor.

Antonio, no, I am not a Mazda tech. I have spent literally hours trying to verify this both on paper and in the real world. I don't have any better paper than what's posted in this thread, but observing the car has been very instructive. This is just how Mazda designed it to work, and I think it's fairly foolish and often unnecessary. Fortunately, our car still handily beats the EPA highway estimate, even in town most of the time, so at least the fuel economy side of it is not bad for us.

Hmmm, it maybe a difference between the non-auto and auto temp control versions. My guess is that they probably did it to extend parts life and keep the windshield clear of fog. Automakers are VERY aware of the gas prices right now, but I think Mazda is more concerned with reliability and safety. I keep my 3's AC on all the time- for exactly the same reasons the manual mentions above- to keep the windshield clear of fog. Given the number of people I see with fogged windows, Mazda is probably tricking the user into thinking the A/C is off when it's on. A means of protecting the stupid people out there form driving around with fogged windows. It makes sense since a 5 would fog up quickly with a a full load of CO2 expelling humans.

Personally I think educating people is the right approach. Unfortunately, manufacturers realize that many people don't read the F$%@ manual, and therefore they need to resort to other tactics to protect themselves from liability.

About 10 years ago I had a pretty heated discussion with this guy who was pre-med at John Hopkins with a 4.0. He, myself and another big guy were driving home from the movie Se7en in my 94 Protege. It was raining and I turned on the A/C to keep the windows clear. The John Hopkin's guy started berading me about how the A/C would have no affect on clearing the windows. This was before cars blocked recirc and turned on the A/C in defrost mode. I'm not much of debater and he ended up putting me in my place and making look like the one who was wrong. A few years later I felt vindicated when my soon to be wife's Honda Civic automatically turned on the A/C with defrost.

It's not only the stupid people Mazda and other manufacturers have to protect themselves from, but the "smart" people who lack common sense.

 

[NYMZ5]

wow. i posted my comment based on every vehicle i've ever owned, both with auto climate control or with manual control. i assumed the mazda worked the same. guess not...

 

[jandree22]

Adding onto this topic, I was wondering... supposing I always use the ACC, therefore the A/C compressor is running, for sake of argument, 100% of the time. Will this wear out the A/C system components any quicker than in most other cars that only cycle it on hot days and/or defrost about 20% of the time?

I'm planning on keeping my 5 for years and years and perhaps it'll be fine, but for some reason I worry that the ACC will wear out the A/C system faster because of it being run continuously.