1996C Class rear headrests nil/op

[mckean]

I can't belive it but, my merc has just developed it's first unserviciability in 225,000km. When I press the switch for the rear headrests to retract you can hear a relay type sound at the parcel shelf but the headrests don't drop regardless of how long you press the switch. Like I said when you press the switch you can hear something working but the headrest don't retract the fuse is good any suggestions would be welcome.

Thanks Mat