Fuse "E", but that covers everything else in the seat as well, so not sure this is the answer. There is also a common ground for both seats, but again this is for all the functions, not just the headrest. If you want to get one of the switches loose I'd recommend diagnosing one and see if you can get to the bottom of it that way. There are 2 wires running to the headrest motor, a pink with green stripe and the other is just pink, you could try jumping B+ and ground to these wires and see if you can get it to move that way.
Does the car have memory seats?
Gilly

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