I solved this problem on 2 hours..... I re-soldered all connections on board (there was missing +12V for invertor).

I pug in all into car....it was lighting few hours and then dead.

Now when I unplug the rear connector from instruments and plug it again it will light for few hours and then get off. I must again unplug and plug the rear connetor. I tried only move with cables going out of connector (but without result).
I dont understand how disconnecting the connector can make this...

I can be wrong invertor or there is still somewhere wrong connection on DC 12V?

thanks!