BMW Repair: AC troubles, compressor clutch, r134

Question
I have a 1996 318is.  The AC keeps blowing fuse #39 which stops the clutch from spinning (I think it's the fuse for the clutch).  Is this a common problem or do I have to troubleshoot?  Do you know what may be causing this?  The AC worked fine all last summer.  This summer I tried using it and had no AC.  I took it in and the R134 was about .8 lbs. low and they replaced the fuse.  It worked fine for a day or so and it stopped working again.  We replace the fuse with a heavier one (10 amp instead of 7.5) but it blew that one too.  Can you please help?  Thanks.  

Answer
Ramon, fuse 15 or (16 with automatic A/C) will supply voltage to the control side of the A/C compressor relay in the power distribution box in the engine compartment (E-Box) and the DME grounds it. The work side is supplied by your fuse 39. Use only 7.5amp fuse please. Disconnect the A/C compressor clutch wire and the active the A/C and see if your fuse blows. If it blows without the Clutch hooked up then you have another issue. If it blows when you hook it up then you have your answer in a shorted clutch or a seized compressor.
-Evan