We have a 2004 Santiam with a wandering fuel gauge. At times we start out with 1/2 tank drive for a few hours, stop, and upon restarting the gauge reads past full. After an hour or so of traveling the gauge repositions to something less than 1/2. The coach is in for service now, if I have the tech replace the sender am I throwing good money after bad or is there really a solid fix for this issue