# A/C Issue



## davek4n6 (Jan 27, 2015)

I have the same exact issue as posted here:

Help! AC stops working after 20 min - Nissanhelp.com Forums

I have a 2007 Altima 2.5S... came across this very strange issue.

The AC air will stop blowing from the vents after 15-20 min of driving.

1) AC works perfectly fine in the beginning. Then gradually less and less air comes out from the vents.
2) The air is constantly cold... and what little air that comes out of the vents after it stops blowing is still very cold.
3) Turning the fan to max, I can hear the blower engage and blow air harder. But no air comes from the vents.
4) Turning OFF the A/C unit but leaving the fan on will start allowing air to come out of the vents. Air that comes out is cold.. seems like residual cold air.
5) After about 5-10 minutes, the AC can be started again and cold air still comes out.

The compressor is new, but this did not fix the issue. I know this model Altima does not have a typical blower motor resistor (which would be my good guess). I wish I could log into the nissanhelp forums but I cannot seem to register there completely. Any help would be much appreciated


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## rogoman (Dec 16, 2004)

Have you tried changing the mode switch to the five different settings and also the defrost switch to feel the air flow with those settings. Also test it with the recirculate switch on.


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## davek4n6 (Jan 27, 2015)

If you mean head, head/floor, floor, defrost/floor, defrost... then yes, I have tried that plus circulate and outside air. Still same issue - only after driving a bit. Has not happened when just idling (unless it reached that point where it blows weak or stops blowing).

The only 'fix' is to turn the a/c button off...wait a few minutes, and then it begins blowing again (not immediately, either). 

It seems to happen when I hit 60 mph quicker than just running around at 30 mph (but it still happens).


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## smj999smj (Jan 1, 2006)

There's a Nissan technical service bulletin for 07-12 Altimas and 09-12 Maximas that sounds like it may apply to your issue. You'll need a set of high and low R-134a gauges to check the system pressures, though. The bulletin is # *NTB12-069* and can be found in the "knowledge base" at NissanHelp.com.

2007 Nissan Altima Service Bulletins - Nissanhelp.com

Another possibility is that the evaporator core is freezing up. This is often caused by a bad thermistor (aka "thermal amp") or a thermistor that needs to be repositioned in the evaporator core. Being a 2007, it's more likely that the TSB applies to your problem, which is apparantly caused by a clogged liquid tank and requires replacement of the A/C condenser and liquid tank to fix the problem.


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