Found long time ago a diagram, where with 2 relays it's possible to keep turning lights on, unless you use them.
Can't find it anymore...
Help....

I don't have a diagram I can post here, but the idea is to have a normally closed relay contact supplying 12v to the turn signal bulbs.  The coil of the relay is energized by the turn signal flasher.  The result is that instead of the turn signal flasher turning on the bulbs, it turns them off.

Should be a fairly easy modification.

If you run with the turn signals on all of the time with incandescent bulbs then they will generate enough heat to eventually warp the turn signal lenses. I've seen it happen on bikes with Run-n-Lites that use 1157 bulbs and keep the low power filament on all of the time.

Thanks for the warning Duck

And the diagram should be somewhere on this site, but lost the location.
I can make my own, but was too lazy

Reminds me of the blonde asked by her boyfriend to check if the turn signals were working 
"yes. it's good ....."
"oh wait, no it's not now ....:
"hang on a minute, back on again!!!! ............" 

Here's one I did for another bike model forum 
The switch/relay wiring is different but just treat everything else the same 
i.e. use the blue/black and blue/red connections in place of the two wires exiting the switch in the diagram 
LEDs will alleviate the heat issue 
You will also need to do the Relay mod cutting the trace to get the flash rate correct (not because of the LEDs but because the load is now the relay coil instead of a lamp) 
Of course the lamps will actually be flashing 'off' as opposed to flashing 'on'  

Here it is in BMW colours  

Thanks
Got something up and running, but took it down again.
Next the upgrade will be ledlights for the turningsignallights, the upgrade will be some powerresistors on a cooling plate with a fan.
Also in the next upgrade will be a radio with SD and good speakers, and will use the radio remotecontrol to control my electric window. The original switch I don't have, the replacement  works, but has to go.
Also upgrade will be an extra switch to control the fan.
It's about 30 Celcius here at day, bugger getting hot. (and me too)
My taillight has been upgraded, the unused part at the side I placed extra lights, got a bigger taillight now.
An extra brake-light will be added too on top or in the 22Liter box.