Friend who bought the SD brought the car to me today and said the turn signals just stopped working. I checked the wiring and it was all connected properly. Neither the rear,front,or dash turn signals work

checked the fuse box and they were all fine. Had cleaned them with a wire brush just to make sure but still nothing....

help please.....

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Current:
05 E320 CDI
07 GL320 CDI
08 Sprinter
05 Dodge Cummins
01 Dodge Cummins

Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed