'90 740 fuse #5 keeps blowing

[absit4040]

Hi,
Just writing to see if anyone out there has advice for this matter:
Fuse #5 (radio/clock/dome/etc...) 15v on my 1990 740 base keeps blowing. Any tips on what the usual culprit?
Background info: just before all this started to happen (2 days ago) my car battery started badly smoking, thick, rotten egg smelling smoke. Looked like acid was bubbling out the side in one very small area. I replaced the battery, it was still under warranty. Regardless, I tested the alternator and things seemed fine, it was reading 14.22 v at no load and 14.35 under load. But the fuse blew while doing the test too. Also, a few weeks before this my car stereo was working intermittently, most of the time with no problems at all. I'm also concerned about the battery smoking... I'm keeping my fingers crossed that it was a crappy battery and not some sort of battery cable problem, ground problems, etc.
Thanks