Has anyone got an offside tailight wiring diagram?

[CraftyCampers]

I'm installing a rear view camera but want it on constant when driving so I'm wanting to pick up the side light cables on the offside light. Can anyone tell me the two colours of wiring I need to connect it to? I've tested it on a battery and it works but just cannot get it to work off the van wiring. Cheers

 

[rod_vw]

Diagrams and much more here then go to Electrical equipment, just use Google Translate where necessary, but be aware that there are many variations of fitments although your requirement for rear light wiring probably doesn't change much.