When I first joined this board, I realized there are some very knowledgable folks on here that can help with just about any problem you might have.
My 89 190e had the usual minor problem which were quickly solved by help from this board and my own experience.

One thing that was wrong that I was not looking forward to was replacing the vacuum models behind the dash. Had the very common problem of heat from the side vents regardless of the climate control setting.

I was all set to go get the parts yesterday and start the job this morning, but decided to do one more search this time on "vacuum leak" instead of "vacuum module". Call it a 6th sense, but I literally did this on the way out the door.

This search revealed several new posts that talked about a small vacuum line under the hood right next to the fuse box. Apparently several folks found it to be cracked. Once they replaced it the heat stopped and the climate control worked like it was designed.

Bottom line, I lifted the hood, checked the vacuum hose and sure enough it was split. I cut a piece to fit and put it on and my climate control is working as designed now.

The moral here is, use several different search terms to find what you are looking for. I did and it saved me 80 bucks and about 10 hours of labor.

__________________
89 190E
2.6L
Arctic white
Grey leather
Sunroof
Pirelli P400 rubber
Smoked corners