Help with battery and fuse problem
 

I changed out battery on my 1980 gs550L but didnt pay attention to where cables go. The black and the red cables are obvious. But there also are a solid black one and a black and white striped one that somewhat smaller in size attatchments ? I tried the three blacks on negative and the one ref of course on hot post then put 2 blacks on negative and striped and red one on positive . Both no dice. Now think its a fuse thing. How does one open fuse box? Unscrew 2 phillips? Or pop off tab on top? Thanks for any tips