2001 e39 horn problem

[Etwenty1 45]

Got a problem with the horn on my 2001 530i, project car so not sure it’s has worked since I’ve owned it, but now it’s wof time, pulled steering wheel to check wiring and I had a spare so swapped wheel and clock spring, no change, swapped one of the horns over with a known working one, checked fuse #3 - noted the contacts had slight rust, The car did have a cracked screen and a water leak behind dash so now thinking I may have a corroded wiring issue… any other suggestions? Cheers

[NZ00Z3 187]

Have you got the multi-meter out yet to track and trace the 12V's.

Get your wiring diagrams from here:  https://bmwteka.com/wds