My '93 190E 2.6's a/c would not start after I came back from a month of vacation. Before I left, for awhile, the blower fan motor would make a grinding sound, but still somewhat function. It sometimes would not start, and sometimes it does. The a/c worked. When I came back from my vacation, I started the car, and pressed on the a/c button, I don't hear the compressor nor do I hear of feel the aux fan being turned on like it should when I turn on my a/c. My serpentine belt has been slipping for awhile. Bought a new belt for replacement, but haven't gotten to it (must have been 2 month). What can be wrong?