Since my original posting I have had American Service Center, Arlington VA. look at my ML. They said the compressor was internally damage and contaiminated the system - need big time repair. $1900 estimate.

I had prior to that visit with ASC replaced the high pressure line between the compressor and condencer due to a leak at the pressure sensor. I also pulled a vaccum on the system and initiated a re-charge. However the compressor would not engage.

Did not let ASC do the repair, and while driving away the A/C began functioning ... cooling and the compressor was cycling. when I got home I finished charging the system and is functioning fine now.

I suspect I am a victim of the intermitant connection problem that I've seen mensioned in other questions on this forum. How do I find the connection that's at fault and what's the recommended fix?

Thanks for any help