Electric window trouble

Hi all, im a bit new to this so bare with me and be gentle.. here goes

Im in the middle of fitting electric windows to my T5 transporter which were kindly donated from a mk4 golf, so far ive managed to get each window working independently from two separate switches (one each door) but im pulling my hair out trying to fit a third switch to the drivers door to operate the passengers window, don't get me wrong im no idot but seam to be having one hell of a blonde moment and cant figure the wiring for the life of me. Heres a run down of what ive done so far...

Two relays one for up one for down

terminals 30 live out to motor for up and same on the other relay for down

terminals 85 switched live

terminals 87 live in

terminals 87A to earth

terminals 86 to switch

This is where I start to get a bit lost, there a 5 wires on the switch yellow and brown for switch neon (not using at minute), red (again not using) , black switch earth, then the two remaining wires go to terminal 86 on relay one on each for up and down.

I expected to be able to tie in replicated wires from the third switch on the drivers door into the relays for the passengers window but all this does is cancel out the passengers switch and kills all other signals in the process.

Sorry for ranting on for my first post but its really P...ing me off now, please help...