This motor pulls air over the interior temp sensor all the time. If the key is on, the motor should run.
Hope this helps. IF the blower is not functioning properly, you should check the blower regulator and the filter.

------------------
Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM