Audi a6 c7 2014 headlights issues

[Maros M]

Hello guys, I am new here and I am looking for the help with my audi a6 c7 2014 

I've had an water leakage in my front left headlight so I had changed the ballasts on it but still not working, so I have bought new pair of headlights and the fault stil remain 

Faults on headlights are:

Left side headlight doesn't work at all, no indicator,no DRL, no main nothing even though its brand new headlight

Right side showing issue on main beam and DRL

I have been at audi and they cannot locate the fault,they thinking that it is something with wiring harness that goes to headlight 

Has anyone had same issue before, can you guys pls help me ?? It costs me a lot of time and money already pls help