2002 X5 4.4

Couple days ago the self leveling inavtive warning came on. didnt pay too much attention to it. it's happened once before and went away on it's own. Next day the radio isnt turning on. GPS works but no sound. Now i have a dead battery. Checked all fuses ok. Went to look at radio BINGO. The battery box has 4 inches of water in it! Radio soaked, and the 3 electronic boxes soaked. NO idea how water got in there. We did have some heavy rains day before this all started. No idea how it got in though. Any ideas?? nothing is wet(carpeting, inside side compartments.) I took the radio module, and other 3 componets out of battery box and took apart, dried and put back together. When i turned key on it was asking for a 4 number code(i dont know it) i had to wait 10 mins for it to clear in order to start. self lever warning still on and no radio. was the code for the radio? or anti theft? did i wreck those components or do i need to reset something?

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