"I know it must be in Bentley.
But I think you know this stuff cold..."

It is in the Bentley, but not always easy to find. What I know (not cold) I learned from digging into the diagrams. But I still double-check them before posting.

Looking at the '89 diagram, the 25 Amp fuse is NOT shown anywhere near the Battery (Item 1 at Grid B1). Instead you'll find it in the LH 2.4 sub-diagram at grids K4,5 and L4,5. If you don't know what to look for there, go to the Alphabetic listing (390-42) where "Fuse (25A)" is listed at grid L5 as item 212. Back on L5 you'll find 212, with an off-page arrow pointing to item 1, which the Numeric listing on 390-43 identifies as "Battery" — you just have to believe the fuse is attached to the Positive terminal (Faith-based documentation).

Looking at 212 on L5 again, go thru it like the voltage does to a "dot" junction that runs between 214 (LH ECU) 4 and 217 (Fuel relay) 30. When the Fuel relay is energized (2 relays actually), the voltage leaves the relay via terminals 87/1 and 87/2 (shown also as terminals #1 and #2). I think you can follow the lines to see where the relay voltage goes.. Another line from the dot junction goes up to item 211-5. Check the Numeric listing to find out what item 211 is.

The Junction box on the inner fender is identified in the Alpha listing. When you locate it on the diagram you'll see a line coming in from the battery + terminal. That's the other small red wire. Follow the 3 lines leaving the junction box and you'll answer the rest of your question.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.