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Xterra AC stops blowing cold after driving for a while

I have a 2003 Nissan Xterra 4 clyd. My AC will stop blowing cold air after driving for about 15-20 minutes. The light on the controls is still on and seems to be running. If I turn off the AC switch and let it sit for about 5-10 minutes and turn it back on (can hear the compressor kick on) it will blow cold air again for another 15-20 minutes or sometimes less. If I turn the switch too early the compressor won’t turn on. I’ve checked the levels on the freon and had the thermal amplifier replaced. Also the fan clutch was replaced, which I was told by the mechanic that would fix the AC problem. Any help or ideas of what the problem might be will be greatly appreciated.

The next time the AC stops delivering cold air, pull over and look under the passenger side of the vehicle and see if there’s water dripping out of the condensate drain tube under the vehicle for the AC onto the ground. If there’s no water dripping onto the ground, this can cause the evapotator under the dash to ice up and the AC stops working. The fix is to blow out the condensate drain tube with compressed air to remove the blockage.

Tester

Tester,

Thanks for the response. You’re right that when it is not cooling there is no water dripping but when it is cooling then there is water dripping. Would this still indicate a blockage?

@Tester Can this be caused from reduced airflow from cabin filters not being changed? Just a small curiosity. I know the evaporator can get dirty and cause this but I didn’t know if the filters being dirty could.

Yes. It could indicate a partial blockage. If the water isn’t able to drain out fast enough it can accumulate under the evaporator where it comes in contact with evaporator and freezes. Then the humid air being drawn into the system freezes onto the evaporator and the AC stops cooling because there’s little or no air flowing thru the evaporator. Then the ice melts from under the evaporator and then off the evaporator and the AC cools again. Then the cycle repeats itself.

I would first try having the condensate drain tube cleaned out to make sure the water can drain out as quickly as possible. Especially when the humidity is very high.

Tester