I clamped the monovalve hose and still no cold air.. but it is not warm.. it is just room temperature air. I turned it off and turned on the AC and it doesnt blow air anymore. I remember that it does this... sometimes it works.. and sometimes it doesnt work. I checked the fuse and it is not blown. Any help here?

Also I touched my AC pipes coming from the drier and all the lines that is suppose to be supplying the freon are all hot.. and not cold like it should be. I tested my 85' 190e with working AC and the lines are all cold. What are the possible problems?