Can anyone ID this part? Also, please tell where it's located in the car. Is it in front of the driver or passenger?

I'm asking because my 300d seems to like to overheat when it's not blowing out hot air. I have checked the monovalve. It seems coolant might be clogged somewhere and this part might be bad.

Here's the seller's description of the part...

climate control module/actuator unit from an 83 MBZ 300D

Attached Thumbnails

 

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