A repetitive clicking noise from behind the center area of the dash panel is usually caused by a broken stepper motor actuating arm. The actuating arm controls the direction of air flow in the climate control system. Disassembly of the center console will be required to access and change the broken arm with the updated, reinforced part.Google+
Car Problem Reports
Mercedes-Benz CLK55 AMG Broken Stepper Motor Actuating Arm May Cause Clicking Noise From Behind Dash
Mercedes-Benz CLK55 AMG Problem
Average Mileage: 107,500 mi (95,000 mi - 120,000 mi)
This clicking just started for me as well. I found that if I put the vent position in a certain place it will reduce the amount of time the clicking occurs. Will be buying the part and getting this fixed next week at the dealer.
Visitor, 2003 Mercedes-Benz CLK55 AMG, 120,000 mi
clicking in center dash