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I have a 2015 Altima S model and have had issues with my heat and A/C system for a while now... When I first start my car before it moves the air comes out of the vents or defrost just fine...shortly after I start driving the air stops coming out of the vents no matter what the selector is on and at times the blower motor even stops working. Also once the car is warmed up...no matter what the temperature selector is on or whether the AC is on or off or on Max it only blows out hot air and I know the AC is fine! Today during my drive to work, I noticed the fan wasn't working at all then 15 minutes later I switched it to the dash vents turned the fan speed up and could hear the fan blowing just fine although it was barely coming out of the dash vents with the dash vents selected on the panel.

So far I have had the mode control actuator and another actuator replaced...then I finally took it to the stealer...they told me the cabin air filter was totally clogged and the fan was bad. Well...$560 later...car is STILL doing the same thing!!!

I am starting to think the electrical control panel is the problem!

Anyone have simiar HVAC issues in the past?

Thoughts??

Thanks!
 

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It's possible the control head is bad, but they rarely fail. First, with a Manual A/C, the Ambient Sensor in the grille can shut whole the A/C down. If it's open or disconnected, the control head will think the car is in the Yukon and won't let it blow cold on any setting. You can check that on your dash, it's the same sensor that gives you the outside air temp. Second, since it only happens when the car warms up, it's possible you have a stuck TXV Valve that's icing up the evap. That will also cause the kind of fan symptoms you're experiencing. To diagnose it, shut the car off for 10 minutes and see if the A/C works normally again for a bit. If so, the TXV is probably stuck open and turning your evap into an ice-block. Third, your car has what's called a "swash plate" A/C compressor. It's like a variable-compression engine, there's a solenoid driven by the IPDM that changes the piston throw in the compressor, causing it to move more or less freon as needed. That's why gen5 Altima compressors never cycle, the IPDM simply changes the swash setting to reduce the flow to near-nothing. When a swash sticks, there's a dead giveaway for it. The A/C will put out good cold on the minimum fan speed, but as soon as you increase the fan, it goes warm. That's because the swash is stuck at the bottom and can't increase the flow to meet the cooling demand. Lastly, you could have an obstruction in the system that's causing a line or hose to ice up. That will cause symptoms similar to a stuck TXV, but usually a touchy-feely test will reveal an ice block someplace where you can see it. Often that's caused by a broken dessicant bad inside the receiver-drier, which requires removing the lines and back-flushing the whole system. Hope this helps you.
 
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