Instant battery drain

[pcmase]

I have a 92 318i and I've have searched all over the place here and Google for help before posting. The battery(second new one) will not hold charge and when it does it last for an hour or so I've pulled every fuse one by one while doing parasitic drain test with multimeter and only one that make a very little difference is ac compressor so I left it out I've pulled individual parts(radio,amp,climate control,window switches,trunk and hood light) I have also checked trunk wiring and there good. Now yesterday I decide to get a jump start and I got a blast of rotten egg smell and can hear bubbling from battery while car was running I've seen mixed answers on if that's bad or not.i just want to know if there is anyone else who had this issue and can tell me if I missed something or how they fixed theres.thanks in advance(local auto store attempted to check alt and batt but there machine couldn't detect voltage on either batt post or under hood post so alt check never happened possible voltage regulator bad maybe)

[pcmase]

Just check resistance
Neg cable to body- good
Body to engine-good
 Positive to front black box good
Black box to fuse box good
Also did ohms on all the above

Moved to fuse box while messing with switches not sure if I am correct but from positive cable to tops of fuses while hitting buttons and switches I had alot of resistance on ac fuse #20 30amp and central locking fuse unsure of # also noticed previous owner cut the wires to fog lights so covered them up till I order new ones the center console also had two bare wires that go to hazard light buttons so fixed them no idea y they were cut into. My next step is to work up the ambition to squeeze my arm into the starter area to test the posts as I just did the clutch last week and I'm unlucky with a non threaded starter so had to remove it(harder then clutch IMO) but left wire and cable attached

[pcmase]

Lol if I kept talking to myself long enough I could have figured this out quicker come to find out I tracked it back to aux fan and wiring so I pulled fuse and plug and it starts and holds charge and my idle even got better and interior lights brighter just found out my shifter lights up red too bad previous owner cut those wires too easy fix

[dlduke]

There's a lot of satisfaction in figuring things out using your own brain and perseverance. Good job.