Scirocco Central

After hitting a wheelie bin in the dark I'm replacing the indicator unit on the passenger wing mirror and I'm not getting it to work. No problem stripping down wing mirror but indicator unit won't work. This is the second new one I have tried. I'm getting 12V on-off at the car side connector plug. (checking using a 12V bulb). When this plug is plugged in to the socket on the indicator unit there's no indicator lights at all. The mirror movement system operates fine I've read a few reports but nothing quite like this especially when I see 12V at the socket that plugs into the indicator unit. Any help would be appreciated.

Problem solved. I bought a genuine VW replacement part and it worked first time. It wasn't much more expensive than the two OEM parts that didn't. A little bird told me that VW have ways of deterring OEM parts from being used and if so, then it worked. It wasn't a difficult job but perhaps I was lucky in that it must have been a glancing blow and the rest of mirror mechanism was not damaged other than the application of a little super glue on an unseen piece of plastic.