k bimmerdad ill try to explain the best possible way:
the whole black infrastructure that holds the fuses and the relays can be unscrewed, do that, after u do that u will see that all the fuses and relays have cables to them, just chek all of them and push them in tight. Its a good idea if u have some one to help u: for example make some one put the wipers in half speed (where they didint work before) and u move around the cables till the wipers work, that way u will be able to locate the problem zone.
I hope this is helpfull.
greeting fellow beemer man.