w140 AC
I dont know about the 280, but the US version (500)
it is automatic, you set the dials and the system attempst keep that temperature by recirculating and sampling the air going into the little grille by the dome light. When EC is illuminated the compressor is disabled, but all the other functions continue. The heaterd seats are one lamp for low, two lamps fpr high, if you have heated seats in the rear there are identical switches in the arm rest. They time out after while. I never use mine due to the locality, but I pulled the fuse since my dog likes to look out the window and the arm rest is a good place to place your paws.
I dont know about the 280, but the US version (500)
it is automatic, you set the dials and the system attempst keep that temperature by recirculating and sampling the air going into the little grille by the dome light. When EC is illuminated the compressor is disabled, but all the other functions continue. The heaterd seats are one lamp for low, two lamps fpr high, if you have heated seats in the rear there are identical switches in the arm rest. They time out after while. I never use mine due to the locality, but I pulled the fuse since my dog likes to look out the window and the arm rest is a good place to place your paws.
