if you have an electrical problem, as the car starts to loose power from the battery, the ECU will start shutting down systems, accessories, radio, fans, air conditioner, headlights, etc... its like they start to go off one by one. Have your battery tested, and have someone test the voltage on the battery cables themselves. Have the battery tested off and on the car.

You could also examine your fuses for those fans but if a fuse was blown they wouldn't work at all, not come on then go back off again. if a fuse was blown it would just not work at all.

I am dealing with an issue that has your problem as one of the symptoms im having too, and the ECU turning off systems when loosing electrical power is something I learned about today.

you could have bad battery, corroded terminals or cables, or a short in your electrical system somewhere. if you jarred the car badly recently you could even have a bubble inside the battery causing a short.

When the car sits, the battery gains a little bit of charge on its own so that's a possibility of why your air goes off then later it works again.

Sometimes even moisture buildup can cause a short in the electrical system but when it dries out, everything works again. Don't spray water in engine compartment if that's something you already do on occasion.

Your system is likely to use the vacuum lines to control the settings. I would look for a rotted line first. If thats not it then move up the ladder from there.

If you're saying the blower motor is running at the set speed but the airflow goes down as the AC runs, then that's a symptom of a frozen evaporator coil due to low refrigeration charge.

The easiest way to check is to run it until the airflow stops. Then park the car with the AC off but blower running full blast. Look under the car to see if a lot of water is draining out of the AC. That would be the water from melted ice.

If you find that, then the system is low on refrigerant

I agree with the first answer

I have a Honda Civic 2006 with 115k miles. The air conditioning has been fading in and out, and sometimes it won't turn off at all. For example, if i were to turn my air conditioning on full blast, the air will only come out full blast for a couple minutes, then without changing the setting, the air will eventually produce less and less air. And sometimes when I try to turn the air on, it won't turn on at all but then later in the day, it will turn on. Does anyone have a idea what may be wrong?