Hi all, bit of a strange one.

Hot day, I whack on the air conditioning and all is dandy, lovely cold air blasting out of the vents.

Within 20 minutes or so the air in the vents slows to a whisper even though the fan is whirring away. If I completely shut the system down for about 10 minutes, or turn the car off for a while then it works again but only for 20 minutes or so. I’ve carried four the resets by pressing the two buttons but to no avail.

I can’t understand what is wrong, if it was a stuck vent it wouldn’t work at all.

Is it on auto? Does it do it if in manual with a certain vent selected?

Yes it does it on auto and with a specific vent selected

Have you run a check for fault codes?

Yes, sorry I should have mentioned that in the first post. No fault codes thrown up

Maybe the internal temperature sensors have decided the temperature is at/near your desired temperature, hence automatically turning down the fan speed.

What A/C profile are you using, mine's usually set to 'Medium', but over the past few days I've set it to 'High' mode.

Thank you, the fan runs at full speed. I can hear it whirring away but the air coming out of the vents is a whisper. I try cycling through the different vents but it doesn’t help. The only thing that works is shutting it down for a while which is not ideal in this weather!

The evaporator could be freezing up and blocking the air flow. When you switch the A/C off, it melts and drains away so the system works again for a while.

AI tells me this can be:

• blocked cabin filter so there's not enough warm air coming in to keep the evaporator clear

• blocked A/C drain - check there is a puddle of water under the car when you park up on a hot day

• low refrigerant pressure so the evaporator has to get below freezing to achieve low enough air temperatures

• or many possible A/C system component failures

Ahh, interesting. Thank you very much. I’ll investigate