A/C compressor problem
There is no serpentine belt or, to my knowledge, a speed sensor. Initially, the A/C compressor would kick on for about 3-4 minutes before blowing the #5 fuse, which also controlled the blower motor. The system was blowing cold air for those few minutes. Then, it quit coming on altogether, and just the blower motor would run. Your theory that the "Klima" relay may have burned out due to a short in the A/C compressor clutch sounds plausible. I guess I'll try running a jumper directly to the clutch terminal and see if a) the clutch kicks in, and b) if there is an excessively high current draw.
Thanks for your input.
1986 560SEC: 150,000 miles, runs great, but I've got to sell it (too many cars for one man)
1987 560SL: 122,000 miles, used to run poorly, now (thanks to forum), runs great!
1997 GMC Jimmy: Turned out to be a turkey.
1989 T-Bird Super Coupe: 150,000 miles, still runs great. Ford got it right.