A/C problem
 

I am going to explain the problem as best as I can. Here we go:

A/C works well for about 45-60 minutes. Then we notice the sound of the fan increase but the output from the vent decreases and the temperature of the air is higher. When this happens the flow out of the vents is about 30% of what should be flowing.

When this happens we can turn the selector to fresh air and dash and it returns to the proper flow and temperture. This lasts for anywhere from 20-45 minutes and then returns to the 30% flow and high temp with increased fan noise.

Has anyone seen something like this before?

Please help my wife isn't happy which means...well you know.

The evaporator is freezing up

So what is the fix for an evaporator freezing up? Is there a way I can check it to make sure that is what is happening? I forgot to add that when it happens if you shut the car off for about 15-30 min the A/C works fine again. But if you shut it down for 5 min it doesn't return to normal.

The next time it happens can I pull over and see if its frozen?

What causes this condition?

Thank you for the reply. I had a mechanic friend suggest I change the A/C control head which I did but the problem still persists.

Thanks again

I just read up on evaporators freezing up. Would that also cause the drop in blower volume?

Imagine a fan blowing air through a block of ice. Does not happen. Melt the ice and air flow again. The Aspin should have an Evap temp sensor making sure the evap does not freeze of course unless the sensor is bad isself. A scaner that can see this info would tell you if its working on not. Like a bad thermometer.