A/C fails when parked in heat/sun

For the past few months I've noticed an issue with my 2012 Leaf, which I don't ever recall seeing in another thread so I thought I'd throw it out here: when I'm sitting in my Leaf waiting for my wife, "idling" with the A/C on, in the heat of the day in south Florida, the A/C seems to go very lukewarm after 5-10 minutes. Sometimes I've been able to get it restarted by turning the Leaf off, waiting a while, and restarting the car. Today I noticed that it starting make cold air again by itself after I drove a few miles at 45 mph. Originally I thought it might be a little low on freon, but the fact it starts working fine again later, especially while moving, makes me wonder if there isn't an A/C radiator fan that isn't operational. Before I pull out the manuals and start troubleshooting, has anyone else ever experienced this?

I've noticed the A/C not cooling that well when doing a QC charge and waiting with the A/C on my 2011 SL. I have always assumed it was because there is no air flowing thru radiator to cool off.

Over the past month, this has happened to me twice. Both in stop and go traffic on the way home in the blazing sun. Both times, it began working on it own after I had turned the AC off for a while.

Same here... I had just read a recent post, where I thought someone posted information that if the A/C unit gets too cold, i.e. below a certain Celsius Temperature, the A/C switches off. There were also some A/C wiring diagrams posted. Anybody else read that post? Maybe, that is what is happening here, otherwise my A/C works fine and is cold, even at the 75 degrees standard setting. Note: it usually takes about 3 minutes of blowing the luke warm air, before it corrects itself and starts blowing cold. Adjusting the A/C settings i.e. selecting Auto or Re-circulate has no affect, and you need to wait about 3 minutes for the A/C to restart re-blowing cold air. Interesting.

I just noticed this happening this past summer but while driving around. It has happened twice now. The first time it started working again after a few minutes of fiddling. The second time I had to restart the car at a stoplight to get it back as it was getting uncomfortably warm in the car.

If you switch to the power usage you will clearly see that the climate control has gone to zero kW so the A/C system has indeed shut down.

But why? This summer is no hotter than prior summers and I drove the car a lot more back then with no issues. So I am baffled as to why this is just starting to happen. I was wondering if something in the unit needs to be cleaned, age factors, or the fact that my battery just lost its 4th capacity bar.

The unit-too-cold theory sounds plausible but again shouldn't I have seen this in prior years? When I next take the car in I am going to have them do a refrigerant test. Low refrigerant would cause the system to work harder and perhaps cause a shutdown like this. It's the only thing that makes sense to me but we'll see if its a little low.

It would help to know the details (fan setting, temp setting, estimated humidity, etc) from each person who has experienced this, as it may occur only under specific parameters, like minimal airflow through the evaporator in humid weather.

I generally keep the A/C on "AUTO", and I can't take a lot of cold air on my face/throat, so I have it set at 75* usually. Its south Florida, so figure about 90-95% humidity. Outside temperatures 91-92*.

keydiver said:

I generally keep the A/C on "AUTO", and I can't take a lot of cold air on my face/throat, so I have it set at 75* usually. Its south Florida, so figure about 90-95% humidity. Outside temperatures 91-92*.

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I can see you not being able to take cold air on your face. you might want to tone it down a bit. My AC seems to work fine at 78º for most days (average Summer temps currently low 80's) but when temps get over 90, I set it to 84. more than comfortable enough for me and I LOVE the breeze in the face so I usually set it to level one below max speed on the fan and cycle it off occasionally if it gets overwhelming.

some might think this inconvenient but found it MUCH easier to do than playing with the buttons. keep in mind; the off/reset button is THE largest button on my dash. now humidity could be playing a part here. Ours is low most of the Summer (Olympia "averages" 100% humidity every Winter morning)

The other thing I noticed is that speed seems to play a part in how effective the AC is. since the AC is not motor driven, I have to find this statement a bit hard to swallow but maybe its just the quirks of my car. If you didn't see it, I have a phantom climate control system where settings randomly change on their own

keydiver said:

I generally keep the A/C on "AUTO", and I can't take a lot of cold air on my face/throat, so I have it set at 75* usually. Its south Florida, so figure about 90-95% humidity. Outside temperatures 91-92*.

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Do you use leafspy?

The heat will come on in AC mode and the only way you can tell if that is happening is to use leafspy.

I have to turn my set temp down to 64 F or below to keep the heat from kicking in at times.

Yes, I have LeafSpy. Why would the heat come on if its 92* outside, and how can I tell on LeafSpy? I've done that cheap mod to the Climate Control to keep the heat off when I just want fan.

i had the same experience today. I got out of the car and noticed that the middle LED was flashing which tells me, correct me if I'm wrong, that the 12v battery was getting a charge so maybe that has something to do with it?

I noticed the A/C is weak when parked and not in the "ready" mode, don't remember what the technical name is but you get to it by pressing the Start button twice without depressing the brake pedal. A/C works normal while driving or parked in the "ready" mode (green car is lit on the dash).

The Leaf is in the "Ready" mode. I simply pull into a parking spot, put it in Park, and wait 5-10 minutes for my wife to come back out of the store. After a while the A/C turns lukewarm, and the car starts getting more humid inside. I guess I need to pull up the manual and troubleshoot it, as I don't hear any kind of fan starting up to pull air through the condenser.

keydiver said:

Yes, I have LeafSpy. Why would the heat come on if its 92* outside, and how can I tell on LeafSpy? I've done that cheap mod to the Climate Control to keep the heat off when I just want fan.

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In Auto, the LEAF HVAC control will blend both AC and Heat if the set point is too close to the car inside temperature.

Just bad design by Nissan.

In LEAF Spy screen four near the top has display of battery or can be toggled to display BATT, AUX, HETR, and A/C.
You can observe both heater power and A/C power and under some Auto temperature settings both will be using power.

Why I mostly use very cold setting in 60 to 66 range and just turn it off periodically.

But I don't think that is your problem.
If that was the cause seems like you would have noticed it in prior years.
Many ICE vehicles have degraded A/C while parked.
But my 2011 A/C will blow extremely cold air continuoudly even parked in 95F garage.

You may have bad condenser fan or low refrigerant.
My fan has always been a bit noisy kind of a housing flutter, but it still works.

keydiver said:

Yes, I have LeafSpy. Why would the heat come on if its 92* outside, and how can I tell on LeafSpy? I've done that cheap mod to the Climate Control to keep the heat off when I just want fan.

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Why is related to AC minimum power vs set point. If the AC at minimum power would produce colder air than you are asking for the heat kicks in to blend warm air with cold air to hit your set point.

How to see this in leafspy is on screen 4 (look at the dots at the bottom left of leafspy the black 0 is the screen you are on and the other three will be white dots).

On screen 4 you'll either have a gauge with SOC/GIDs/DTE or a gauge with Mote/Aux/Hetr/A/C. You want the one with Hetr and A/C on it so if it doesn't show that tap on the right side of the graph between 80 and 100 marks.

The numbers are on the far right. If Hetr is anything other than 0 the car is wasting energy blending heat into your A/C. It won't happen all the time, it will cut in and out depending on the interplay of fan speed, outside temp, inside temp, requested temp (set point), and solar loading.

If I see the heat kick in on my Leaf I just turn the temp down until it cuts out and then turn the fan up and down to modulate the wind chill effect.

TimLee said:

In Auto, the LEAF HVAC control will blend both AC and Heat if the set point is too close to the car inside temperature.

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It's not limited to Auto. I never use the auto function because I don't like the fan running higher than 5 bars speed.

I've got it in manual mode A/C and keep the fan speed set at 1 to 4 most of the time, maybe hit 5 if it is an unusual record hot day.

I started out with my setpoint at 70-74 but then I noticed the heat kicking in on leafspy so now my setpoint is in the 60s.

Even with it on manual, A/C, 65F fan speed 4 if it is cool enough the heat will kick in if I leave it running long enough.

I tend to think the A/C blowing Luke Warm air intermittently has nothing to do with a Hardware malfunction, but it prevents the system from getting too cold. I wish it could be fixed with a software/programming update.

dsh said:

I tend to think the situation with the A/C blowing Luke Warm has nothing to do with Hardware malfunction, but rather a software/programming issue. I noticed the individuals who are complaining reside in hot states i.e. AZ, FL, TX and these are the vehicles with the original A/C and Heater design. These 2011/2012 cars where never meant to be used in Hot Temperature regions, but are better tuned to the temperate climates of Japan.

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Well, I reside in one of those "hot states" and don't have a problem with cold A/C. However, I do agree with you that it is a normal function of car HVAC systems to cycle through moderate temperatures occasionally (I just don't see it happen for long).

Stanton said:

However, I do agree with you that it is a normal function of car HVAC systems to cycle through moderate temperatures occasionally (I just don't see it happen for long).

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Pretty sure that's done to melt any ice which might've formed in the evaporator. Once it ices up the amount of cooling really drops off... perhaps that's what is happening here. Might the drain line be partially plugged?

Any other owners come across this issue of the AC blowing warm air, but after a couple minutes the compressor kicks back in and starts blowing cold again? Any idea what the best AC temperature Set Point is, in Arizona Summer heat 114 degrees?