For which market is your 2008 S5? In the North America, 2008 models were still B7-based; ROW (including Europe), 2008 was the first year for B8 models. Your Fuse Panel F (right rear luggage compartment) looks like early B8.
Assuming yours is a B8 platform, Fuse Panel A is the assembly attached to the starter battery positive terminal (under the spare tire/wheel in the trunk).
Fuse 1 here powers other things, like Fuse Panel F Carrier 2 (black) and J807 (12V sockets relay). If your 12V sockets all work, the problem is not likely with 110A Fuse 1. --g
video shows exactly what I’m talking about I already took that plastic panel off holding F and flipped it upside down, the connector is In and fully seaded.. short of pulling that middle brown section off and checking the power pin individually I figured some relay or something else is triggering this no power to be sent
theirs no sign of water damage at all
if no power is being sent to those fuses then of course my mmi and other things wouldn’t work like my passenger door and rear view camera I scanned on vcds and did optical loop test all came up ERROR, will update vcds scan but clearly the fuses are the issue
The wiring diagram tells us that one of the two red cables in your picture goes to splice (B272) in the wiring harness; from there, one wire goes to Fuse Carrier 3 (brown), the other to the rear window defroster 40A fuse S41 (H in the diagram).
If you don't find any power on the hot side of the brown fuse carrier ST3, it's because it's being interrupted in the wire harness between Fuse Panel A and the brown fuse carrier, possible at B272. --g