Replaced the evaporator core in my 1987 300E over the past few days without the use of a manual. The results of my research here was all that I needed. The worst part of the job was getting the AC compressor to restart when adding refrigerant, it refused to kick in. After checking fuses, relays, sensor switches, vaccuum lines, bypassing switches to make sure the clutch worked, I was about to give up until I spent another hour here and found a post that said to MAKE SURE THE TACH IS RECONNECTED, OR THE RELAY WONT KICK THE COMPRESSOR CLUTCH IN. Well, since I tore out the dash, and was not about to put it back together without checking everything first, needless to say, my tach was disconnected. That was my problem, reconnected it and everything was fine. Many thanks to all of the posters here.