One out of three rear head restraints

[Tim Smith]

I wonder if anybody out there can explain the workings of the rear head restraint flip-down system, and before I get a load of replies saying "there's a button on the dashboard", I seem to have only one fully operational drop-down head rest.
I suspect that the problem may be electrical, as the non functioning units are on the nearside and the central one which share the same seat-back.
Has anybody had this issue, and if so, how was it sorted.

 

[weds]

One my E class estate only the centre headrest drop down for better visibility.. Hardly ever use it because no one raises the centre headrest when they get in..

 

[GJP]

My 2005 S211 was the same - just the centre one (for visibility I assumed).

Ironically, on my '68 E400d estate it's only the outside ones that drop - so, not the middle one.

G