I have recently brought a vauxhall astra sxi 1.6 1999. The problem is that the fuel gage doesnt move therefore i dont know how much petrol iv got/usuing. ive tried sorting it by buying a new fuel sender unit which i changed and it didnt do anything different so got my dad to look at the fuses and he said they were fine, after he looked at them n the fuel sender unit was done the dash board lights no longer work. im stuck i really dont know what to do ?