Good day

The intermittent wiper feature has stopped working--no fuses blown.

Shall be extremely grateful for any assistance regarding diagnosing right thing(s) to look for---. is it controlled by one of the little black boxes behind the fusebox? if so how does one know which one to change?

maybe there exists a fairly comon cause and cure known by MB owners.

Thank you for any and all assistance.

Ed (S Africa)