BMW Repair: Air-con, e34 bmw, electromagnetic clutch

Question
Hi

I have a 1993 525i touring E34 BMW. The horn and air-con were not working. Fuse 9 had blown. I replaced it and it blew again. Turns out that the air-con electromagnetic clutch has gone short circuit. Disconnecting the wire to the compressor stopped the fuse 9 from blowing. So I now have a working horn. On investigation the disconnected wire is always at +12V, connected to fuse 9. This can't be right can it? Surely there must be some sort of control system switching this on and off depending on temperature and dash settings? I look forward to your thoughts. Thanks in advance.

Best regards

Cliff

Answer
The clutch gets power from the compesser relay when needed.
It shouldnt be on all the time unless the processer is turning on the relay or the relay is stuck on.
Either way that shouldnt blow the fuse unless the compresser cluth has a problem.
Maybe it shorted out from being on all the time.