Indicators don't flash
 

I would like to install only the 2 direction indicators in the front.
I connect all cabels, plugs and also the flash relais.
But the bulbs don't flash they only shine permanantly.
What can I do ?

The flasher relay is set up for four bulbs. With only two bulbs, there's not enough resistance to make the flasher work.

OK when I simulate the 2 rear indicators with 2 resistance (5W/13V = 0,420A; 13V/0,42A = 31Ohm/5W) with appr. 33Ohm/5W it can work?

Yes, or you can try an LED flasher.
Most people just hook up bulbs and mount them out of sight.

OK the flashing works with 33ohm/5W but a little bit to slow
may be try some 22ohm resistance