the a/c to blows warm air on the drivers side in sunlight or high ext temp on 2000 Mercedes-Benz S430

In summer at temps above 75 the a/c on drivers side cools at stops and warms after take off. Also in tunnels or under passes it cools until you drive back into sunlight. Passenger side is fine. Temp setting doesn't matter.

Asked by for the 2000 Mercedes-Benz S430