hello guys my friend has gmc 3500 from 1988 with the 5.7 l gas engine and we are trying to fix the gas level indicator in the cluster which the needle is moved to the right side past the full tank indicator and stays there and it wont move at all ..... now before that he says it moved but it wasn't an accurate reading and we now for sure that we have voltage back there tested with test light how should we proceed to fix this issue ...... thank in advance