Checking heating and ventilation (Audi 100 C4)

Turn the left control of the air access and ventilation switch slowly from left to right: air access opens, the fan increases speed by 4 steps.

Turn the middle rotary control to the right, which changes the air temperature: the heating capacity increases.

Air access occurs through a heat exchanger.

Turn the regulator to the left: the heating capacity decreases. The air flow bypasses the heat exchanger.

The regulator on the right is set under the scale symbols to distribute the air flow in turn: from the left extreme position, moving to the right, the following air supply occurs one after another: a) from the nozzles in the middle of the instrument panel; b) from the nozzles in the foot area; c) from heated nozzles under the windshield.

In the regulator positions b) and c), a certain amount of air is additionally supplied from the middle nozzles, if they are not blocked by the rolling wheel.