Heated rear window wiring

[monitormagic]

Hi I've got a m59 Berlingo forte multispace 53 reg. I've got no voltage reaching the rear demister but I do have the heated mirrors working and I think these 2 things are linked at the same fuse which tests ok. The wires for the rear demister come out of the tailgate and disappear inside the body of the car. Has anyone got a wiring diagram of harness diagram I could follow ?   It's a 2l hdi. Thanks