Volvo Repair: A/C Compressor, volvo 850, highside

Question
I have a Volvo 850 / 1995 Turbo, am trying to locate the upper intake pipe for the A/C, I can only see the lower valve for charging the freon. Also sometimes the A/C when turned on works well - very cold and sometimes it just blows hot air, what could the problem be?

Answer
Kagumbae, Most likely the clutch is the problem.  The next time it blows hot air, see if the clutch is engaged.  If not, carefully tap it with a pry bar.  If it engages, then that is the problem.  Its cheaper in the long run to replace the compress instead of just the clutch.  There is only one port on the 850's,  there is no highside port. Roger