It's a freeze up of the core. Park it and the ice melts off and its fine the next day.
I've had a Taurus that did it once, and a Cadilac that did it multiple times.
It always happened on long highway trips when it was really hot and humid. On the highway the system has a chance to get really cold behind the dash with the sustained airflow over the condensor core. Add in a ton of water on the core avaiable to freeze and you can get a huge block of ice very quickly.
The system doesn't monitor the core, so it only sees the warm air (since it's not passing through ice) in the box and keeps the compressor going, further icing things up until it finally cuts out from the pressure switch and you have nothing but a block of ice on the core.
I've had a Taurus that did it once, and a Cadilac that did it multiple times.
It always happened on long highway trips when it was really hot and humid. On the highway the system has a chance to get really cold behind the dash with the sustained airflow over the condensor core. Add in a ton of water on the core avaiable to freeze and you can get a huge block of ice very quickly.
The system doesn't monitor the core, so it only sees the warm air (since it's not passing through ice) in the box and keeps the compressor going, further icing things up until it finally cuts out from the pressure switch and you have nothing but a block of ice on the core.
