Air flow across the in-car temp sensor mounted in the dome lamp is designed to allow for the variable speeds from the blower motor.
The system is designed to keep the temp(inside the car) with-in 1 deg of the temp wheel after 10 minutes at 15 inches from the inside roof panel. Blower speed will only slow down WHEN the system has gotten with-in that 1 deg spec.
The 1994 & later cars with the "micro-filter" dust system do have a different electronic blower regulator & seem to keep the blower at a higher speed longer than the 1993 & earlier cars did.
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
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190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)