Help with wiring inside box of aquarite.

[Smudge 52]

Can someone tell me what wires go to what terminals on the two black square componants with the hex head screw in the center (dont know what they are, maybe diodes?) in the upper right side of the box. There are six wires, three go to one and three go to another, just below the other componant. If someone would be so kind as to pop the cover off and let me know what color goes to what terminal and what terminal remains blank it would be greatly appreciated. Thank You. The wiress are org,red,blk,yl,another red and another black.