It appears that if this bolt is loose, the fuseblock is poorly grounded. So.... the ignition relays do not work, and not much else works. What is the purpose of this bolt, and how do I "read" the orange locking tab , service manual is unclear on this. Thanks in advance for the help/advice.

 

I respectfully disagree. The service manual is very clear on this. It says ...tighten bolts until orange "fulltight" mark appears and then retighten to specified torque as required. The torque spec is 26-43 inch-pounds. The service manual continues ... Caution: Do not overtighten bolts, otherwise they may be damaged.

 

Ok, you are correct, I did not state my issue clearly, the manual says what you say, but tells me nothing about the purpose/function of this very special bolt with the orange tab. Orange tab seems to be visible at all times even with the bolt finger loose. More interested in the function/purpose of this bolt.
Again, help on understanding this bolt greatly appreciated.
That is my minor issue with the otherwise excellent service manual for this car.