Didn't see this until today, sorry...
You can't use the input from the stalk as that is uni-directional as it is picking up the power from the Relay, as the power for both turns, and the 4-way.
You would be better served in using a wire from the left or right side bulbs that run from the switch as that would be the power to light the bulbs.
That would be the black/white (left) or the black/green (right) you may be able to get them out of the Stalk as they are sided that way. When the flasher is selected then you would have both flashing as the 4-way powers Both sides.
VW went cheap, and only used one signal path to power the bulb and that was the input side or ground side of the picked relay to power both the 4-way and the left or right with but one wire and one bulb...albeit they did use 2 power sources for the separate sides as the low fuse for the 4-way and the higher fuse for the turns.
You still may see the wonky glow of the turns if you short out that wire, which is why I always suggest to heat shrink that thing to prevent the dreaded I only moved my switch why do my turns only glow..(because the power wire shorted to frame taking out the higher fuse.).... The black/blue wire:

You can't use the input from the stalk as that is uni-directional as it is picking up the power from the Relay, as the power for both turns, and the 4-way.
You would be better served in using a wire from the left or right side bulbs that run from the switch as that would be the power to light the bulbs.
That would be the black/white (left) or the black/green (right) you may be able to get them out of the Stalk as they are sided that way. When the flasher is selected then you would have both flashing as the 4-way powers Both sides.
VW went cheap, and only used one signal path to power the bulb and that was the input side or ground side of the picked relay to power both the 4-way and the left or right with but one wire and one bulb...albeit they did use 2 power sources for the separate sides as the low fuse for the 4-way and the higher fuse for the turns.
You still may see the wonky glow of the turns if you short out that wire, which is why I always suggest to heat shrink that thing to prevent the dreaded I only moved my switch why do my turns only glow..(because the power wire shorted to frame taking out the higher fuse.).... The black/blue wire:
