A/C cutting out

Gang,

About a month ago I noticed I lost my A/C and blower. Basically all the lights came on but nothing out of the vents. This seems to be a common problem on the MkIII RR's. Using this great board I figured out that the likely culprit was a bad Final Stage Resistor.

I was all set to pick up part # JGO 000021 at the dealer, pay my 100 clams, and attempt to swap out the part myself. [The dealer wanted 3 hours labor @$185/hr. My independent shop wanted 4 hours labor.]

Funny thing is is that the A/C mysteriously started working again. No real reason that I can detect.

So, now what? Anybody come across this? Is something loose that I can check easily? Any and all thoughtful suggestions welcome.

Thanks all.

ketel