R170 Indicators Not Working, 4way Flashers Do

[atttim]

1.Bulb warning light stays ON
2.Indicate left or right, no green warning lights showing, no clicking heard. No bulbs activated LH or RH !!
3.Activate 4Way Flasher Switch everything working correctly to the bulbs, and both green warning lights working in instrument panel.
I checked Fuse 12 in fuse box behind light switch area, all ok !!

Any advice where to start looking and locations of devices to check why the normal indicator system is not working ?? Refers to SLK R170 .

Thanks