GPZ 500 lighting failure of the year 90

Hello, I have caught a GPZ 500 and I have a problem with the lighting .....
This motorcycle has automatic lighting of the headlights as soon as the engine starts. And stop when it leaves me lying down and the lights are not lit, I suppose that it carries some turned on which I would like to annul to put the lights with a switch ....
I have lowered the workshop manual but it is in English and I do not understand that
I I would do a great favor because I tried to translate the manual but after two days I had only translated 3 straws and I almost hit him fire for despair ....

Thank you very much in advance.