Mercedes-Benz 500 SEC Operator's Manual page 23

Automatic Climate Control
Left side passenger compartment:
1 Temperature selector
2 Temperature display
3 Automatic mode
4 Air distribution buttons
5 Defrost
6 Residual engine heat
utilization
7 Air recirculation
8 Air volume selector
9 Economy
10 Selection switch
11 Off
Right side passenger
compartment:
12 Temperature selector
13 Temperature display
14 Automatic mode
15 Air distribution buttons
23