I just checked A/C operation on my 2.5 sv. When heat is on and on AUTO, the A/C compressor still kicked on without the light coming on, but by pressing A/C button twice the compressor disengages. Once set, I was able to shut off and restart the car multiple times without having the compressor engage again. Just one more bug..
So this glitch only occurs when using Auto, correct?
It was boggling my mind why I never noticed this issue, but I guess it's because I never use Auto to begin with.
I don't know for sure if not using auto works yet. I need to try LMK5's method for testing for the problem and then try auto off to compare. This morning I tried the method but forgot to put it in auto mode first. What happened for me is when it dropped down to 60 degrees I had cold air coming out of the vents and could hear a slight whine. When I raised the temp up to 70 the whine went away. Double pressing the AC button didn't seem to have any effect in temp or sound but again, I had forgot to put it in auto mode. Outside air temp was 4 degrees.
I assume the sound of the compressor kicking in is obvious and more than the whine I heard but can someone confirm?
BTW, my MPG is 22.6 per the computer. No highway miles yet and I only have 137 miles on the car.
It is my experience that it would be difficult or impossible the hear the compressor while driving. I would have to be stopped, idling, have the radio off and the climate-control fan on a low speed.
Also, I would not describe the sound as a whine. Sounds like that might be something caused by a lubricant or tolerances made thicker or tighter by the cold weather.
I also wonder if it is even possible to run the A/C compressor when it is that cold. I would not be surprised if there is a thermal switch that prevents running it below a certain outside temperature.
Last edited by Drifter_Yank; 01-03-2013 at 12:59 PM.
I just checked A/C operation on my 2.5 sv. When heat is on and on AUTO, the A/C compressor still kicked on without the light coming on, but by pressing A/C button twice the compressor disengages. Once set, I was able to shut off and restart the car multiple times without having the compressor engage again. Just one more bug..
Guys,
If you read page 4-30 of the manual, it is telling us that by design, the AC is always on, even when heating. Note the section of the manual on page 4-30 called "Heating (A/C OFF)" which I included earlier. The problem is that the AC light is not coming on so we can't turn the AC off with one press of the AC button as the manual suggests. We have to fool the system by first engaging the AC switch (first press) then turning off the light (second press).
From the system "OFF" state, I can press the fan increase button - this turns on the fan / system.
If I turn the temperature down low, the AC compressor definitely comes on. The "double-press" of the AC button mentioned in this thread turns the compressor off.
I (sort of) understand the AC coming on in AUTO mode IF I turn the temp low enough to need it. However, it should illuminate the AC light at that point. It also SHOULD NOT turn on the AC if the temp is set high, or if only the fan has been turned on without the AUTO being pressed. If the outside temperature is comfortably low, I should be able to easily enable ambient (unheated or cooled) airflow from the system w/o having to guess whether AC is being used needlessly (and wastefully).
On my 3.5 SL... with the AUTO on (all the time) when the A/C button gets depressed it's light comes on AND the compressor kicks in. This is verified by myself standing outside the car, with the hood open and hearing it kick on.....when the same A/C switch is depressed a second time the compressor turns off, as verified by the same method.
The second way I verified this is by sitting in the idling car and wacthing the tachometer as I press and depress the A/C button.....I can clearly see a momentary drop in idle RPM when the A/C is on and a subsequent momentary rise when the A/C is turned off.
As I've written before, perhaps this is a 2.5 issue and not a 3.5 issue.
If you read page 4-30 of the manual, it is telling us that by design, the AC is always on, even when heating. Note the section of the manual on page 4-30 called "Heating (A/C OFF)" which I included earlier. The problem is that the AC light is not coming on so we can't turn the AC off with one press of the AC button as the manual suggests. We have to fool the system by first engaging the AC switch (first press) then turning off the light (second press).
You're wrong......I read the manual and IT DOES NOT SAY THAT THE A/C IS ALWAYS ON!!!!!
Below is a copy of the page that discusses AUTO HEATING....please read the first line:
Heating (A/C OFF)
The air conditioner does not activate. When you
need to heat only, use this mode.
1. Press the A/C button. (A/C OFF will be
displayed and A/C indicator will turn off.)
2. Turn the temperature control dial to set the
desired temperature.
● The temperature of the passenger compartment
will be maintained automatically. Air
flow distribution and fan speed are also controlled
automatically.
● Do not set the temperature lower than the
outside air temperature. Otherwise, the system
may not work properly.
You're wrong......I read the manual and IT DOES NOT SAY THAT THE A/C IS ALWAYS ON!!!!!
Below is a copy of the page that discusses AUTO HEATING....please read the first line:
Heating (A/C OFF)
The air conditioner does not activate. When you
need to heat only, use this mode.
1. Press the A/C button. (A/C OFF will be
displayed and A/C indicator will turn off.)
2. Turn the temperature control dial to set the
desired temperature.
● The temperature of the passenger compartment
will be maintained automatically. Air
flow distribution and fan speed are also controlled
automatically.
● Do not set the temperature lower than the
outside air temperature. Otherwise, the system
may not work properly.
The plot thickens….
I have a question about the text I have in bold above. Is there an “AC off” icon displayed on one of the screens or is it just the indicator light on the AC button that turns on and off? The way I read that text suggests that there is an icon that lights up but I’ve never seen it no matter how many buttons I press.
YES...you are correct. There is NO text on the temperature control screen that reads "A/C Off"....perhaps in earlier years there was and that was never removed from the manual. I too ONLY have the amber indicator light on the A/C button.
But never the less.....on my car, if the amber light is not on then the A/C system (ie: compressor) is not on.....exactly as the manual says "NOT ON"
For thsoe that think they have a problem....try parking the car in your garage, open the hood and have someone else press the A/C button while you stand by the engine and listen for the CLEARLY AUDIBLE sound of the compressor kicking on. IF you hear it then you'll know that before the A/C button was pressed the compressor was NOT on.
Your ears will tell you what's what.....simple!...try it and report back.
This, in isolation, is not a foolproof test - when the AC circuit is enabled, the compressor cycles on and off. If, at the moment you toggle the button to AC ON, the compressor is already running, you won't initially hear the click. Here is a better test - note the compressor cycle times can be relatively short (10-15 seconds "on" time) or significantly longer:
1. Hood up, start the car, make sure the climate control system is off. listen for the AC compressor on / off cycling - you shouldn't here any.
2. Press the AUTO button and set the temp to a low number - you should now hear cycling of the compressor. Note that the AC light is not lit.
3. Press the AC button, and the light will come on. No change in the cycling of the compressor.
4. Press the AC button again, light will be off, and no more cycling will be heard.
In my testing, switching from climate control OFF to fan only (by pressing the fan increase button) and lowering the temp control will turn on the AC compressor just like pressing AUTO does, with no indicator light. This is my biggest complaint - if I just press the FAN button, no AC should ever happen. It didn't on my previous car (2005 Accord Hybrid) with auto climate control...
Quote:
Originally Posted by rob175
For thsoe that think they have a problem....try parking the car in your garage, open the hood and have someone else press the A/C button while you stand by the engine and listen for the CLEARLY AUDIBLE sound of the compressor kicking on. IF you hear it then you'll know that before the A/C button was pressed the compressor was NOT on.
Your ears will tell you what's what.....simple!...try it and report back.
__________________
2013 Altima 3.5SL, Cayenne Red, Beige Leather, BT trunk light mod / footwell light mod, Racing Line FSTB
You're wrong......I read the manual and IT DOES NOT SAY THAT THE A/C IS ALWAYS ON!!!!!
Below is a copy of the page that discusses AUTO HEATING....please read the first line:
Heating (A/C OFF)
The air conditioner does not activate. When you
need to heat only, use this mode.
1. Press the A/C button. (A/C OFF will be
displayed and A/C indicator will turn off.)
2. Turn the temperature control dial to set the
desired temperature.
● The temperature of the passenger compartment
will be maintained automatically. Air
flow distribution and fan speed are also controlled
automatically.
● Do not set the temperature lower than the
outside air temperature. Otherwise, the system
may not work properly.
I'll give it one more shot. The manual tells us that you must do something special to have heating with the AC off. The first line that you refer to above is the definition of the mode, and the rest of the text tells you how to engage that mode.
Look at my attachment of page 4-30 below and look at the very first part, it says "Cooling and/or dehumidified heating." The only way to provide dehumidified heating is to have the AC running. That's why it is coupled in the same section as "cooling." I hope you agree so far.
Then they include another section solely for heating with AC off called "Heating (AC Off)". Ask yourself this: Why would they discuss heating a second time on the same page of the manual? It is because they are trying to show you how to run heating without the AC on, which is not the default behavior when heating. In bullet #1, they tell you that you should get the "AC off" display (which no one gets). You don't get this display, correct? Note that it also mentions that the AC indicator will go off. That's the light on the AC button.
So, from the manual itself, we absolutely know that the AC light off and AC Off display are 2 separate things that should happen in order to have heating without the AC on, but no one on this forum is seeing this behavior.
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