I'm having a hard time figuring out why my gauge does this. I put enough gas in to where it spills out of the fill tube, yet it won't read even to half. I have dual tanks, I'm unsure of the condition of the right tank. I'm only using the left (driverside) tank. They look to be the same size, so why wouldn't it read to at least half? I'm mildly clueless when it comes to wiring, so hopefully one of you experienced guys could help me. Thanks ahead of time.