All of a sudden no backup lights on my W210 1997 E420....I have replaced fuses, checked bulbs but to no avail. No warning indicator lights at dash (defective bulb) or any such thing. All else works, including turn signals and such. What could this be? I am hoping not the integrated backup switch in the shift console. Any ideas as where I could start? I did check the wiring in the trunk and it all seems good with no breaks.

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Norm K.
'97 E420 Sport
'06 E350 Sedan
'67 Mustang Coupe
'70 F-250
'15 VW Jetta