It's a 10amp (as you may already know from re-reading the posts). You must be on post March 2000 wiring I'm guessing?
Engine management is 15A, F30 as well as F33 which is a 3A.
Might be worth checking those too. Could also try leaving the battery disconnected for a while, re-connect and see what happens.
Could also be the power hold relay playing up. A lot of stuff goes through that. C168 on your diagram there.
Difficult to say what to try/do without having the car in front of you! Just remember try one thing at a time, don't change two things at once :wink: