Thanks for the warm welcome and replies.
Firstly its a 2005 UK model. I have already disconnected the battery left it for a good while and then disconnected the plugs under the seat after a reset it has come back on.
I don't believe the white plug is connected to the heated seat on mine as the heated seat still works on the passenger side.
I might have another go at disconnecting them all and checking the plugs and connections within again, failing that it looks like a trip to Nissan to read the fault code at least that will give me a clue as to the cause.
Thanks again for your help.