Failure at Grand Cherokee 2000 4.7lt V8 4x4

That such a good day what happens is the following: when my Cherokee turns on, the needles and witnesses turn on, even there we are there because they do it and then they are chosen, but in mine sometimes it does and sometimes they fall to zero does not mark me revolutions or the level of gasoline, temperature, oil, battery and the witnesses are activated, but if I go with it I can go with it. Therefore, that is dangerous, to let friends thank you for the next help you give me