on my 1987 190e 16v, I have cold air coming from under the pass. seat, is there some thing that I need to hook up. I have warm air coming out of the other vents but not from the seat. I also have a question about the center vents...are they only suppose to have cool air come out of them? and finally I have a button to the left of my gages, with a light bulb on it, what does it do?

Sorry for all the questions, still very new to the mercedes world? Loving every minute of it. Best $500 dollar investment i ever made. car is in great shape...