Im really confused with the readings shown by the solar panel. it shows random readings even though it is completely covered. maybe there's something wrong in the wiring.
so heres the wiring
Can you upload the image here. See the sticky post on how to display images inline.
I'm on a phone right now and copy-pasting links is awkward.
That image is spectacularly unhelpful. Without any explanation of what the wires are connected to, it's useless. Even if you try to explain to us what the yellow wires are (and where the yellow wire goes that just crosses the picture without connecting to anything in the picture) it's not helpful.
Draw a schematic. It doesn't have to be fancy or use standardized symbols. Just anything on a piece of paper will be more helpful than that photo. Often the act of drawing the schematic will find your error.