That just happened to me on Friday of Memorial Weekend going north on I5 in the middle of nowhere in my '89. Outside temp was close to 90 degrees. Traveling 85-90 mph, a/c on high. Symptoms: sudden terrible burning smell, followed by noise in front of passenger seat. Pulled over, lifted the hood, noticed black sticky tar-like substance in a scatter pattern on the a/c drier and hoses. At idle, the a/c compressor was making noise and emitting burning smell.
I disconnected the electrical plug to disingauge the clutch. Smell dimminished, noise continued. I cut off the belt...no more noise.....no more problems...of course, no more cool air.