Suzuki Club UK

Hi, my rear window demister only seems to be working on the lower half of my 2011 Vitara. There seems to be two connection points, guessing one feeds each half, but may be wrong. I've checked with a meter and get 13+ volts on one side and zero volts on the other side.
Does anyone have any ideas, know where the wires split to feed each half or have a wiring diagram?...cheers, Jeffers