Air con/ blower system fault

Hello all

I was driving down the m6 yesterday all happy when I noticed the car suddenly got cold and the windows started to steam up.

My car is a 16 plate 1 litre petrol and has a basic air con push button system.

It seems like no matter what nobs I turned the direction of air or temperature of air didn't change. You could hear the air and blower but none seemed to come into the car.

On recirc air it was roaring onto the windscreen and on fresh it hardly did anything. It feels like the air is by passing the actual heater/ conditioned side of things and is just venting out some where. When you switched to the dash vents nothing really came out.

Half way through the trip it suddenly started working, the car got warm and all windows cleared instantly. The direction worked the temp worked. Then it broke again.

I've never dealt with Air con systems apart from charging. Not a clue where to start.

Any help appreciated.

Hi, welcome.
I am not familiar with the "new" C3's but the air con's principal of operation is usually the same.
If your air con has push buttons I would assume it runs servos for the air direction and temp flaps. Going on past experience, the gears of these servo often strip.
Run the recirculation and air direction selector through out the range with the fan on minimum and the engine not running. You are trying to hear if there is any continuous clicking or clacking coming from under the dash. The sound of plastic gears not meshing. Often you might hear this sound on start up as the ECU tries to set the broken flap servo.
If you car has manual knob controls, well I've got no ideas.