Battery cable issue

Hi gang. I discovered why my 1994 Spider seemed to have a dead battery. The positive cable was totally messed up in the bay in front of the left wheel. When I got in there, the plastic fuse cover was totally unscrewed, the fuse was bent but not broken and it was disconnected from the other end AFAIK. How did it get in this state from the dealer in October? I have only driven it 3, now 4 times. It failed on me a few blocks from home after dark and I had the joy of getting a push off to the curb. Eventually jumped it with my massive Bosch 27F (R) battery (book) but may have cooked the Alpine stereo in the process. I think it was on when it failed and the last time trying to jump in my driveway smoked one of my cheap cables a little. Ferrari is fine and I just checked the fuses. I also have no high beams AFIK and don't want to break my light switch stalk. Once I got it cabled up properly it ran great. Went for a massive tour downtown with a friend and had a great time. It should go in storage on Wednesday, weather permitting. No heat or power so I will turn the power knob off and see what happens in February for the belt service. Now the other thing is, I found another black cable under there, smaller diameter with a bullet or push connect style fitting. It looked loose too so I reconnected it. But no stereo at all. it has Sirius and I just saw the box behind the center side panel in cockpit. Is this messing up the ground? Should I disconnect that extra black cable and try the stereo again? For a sweet 3000 mile car I'm finding some real winners. Also had to tighten a hose clamp on the top of the engine, and found an extra fuse sitting by the fuse panel in the trunk. Current battery is Optima red top and a nice green charge after 24 hours on tender. Properly connected!

 

And now snow? Crap. But it should go into storage on Wednesday weather permitting. I slept ok, but this stero thing has me obsessing. I suppose I can work on it in storage but there is no power or heat out there. Maybe I can pirate off a light fixture? Anyway, any help on that extra push together connector? It may be part of the Sirius options but looked disconnected when I got to the battery. I put it together and nothing. It had two big and one small terminals in it. Sorry but pics are not available. About 1/4 inch in diameter. Also I think I heard the servos click a little when I took the face plate off and reattatched it. Door servos clicked when I removed and replaced fuse. Working fine there. Any experience with using those front terminals on an Optima? I think they were using one, if poorly. I went back to the posts and turned the battery back straight so it could be clamped in properly. Bouncing around may have been a factor. I'm shocked about this, no pun intended haha.