1998 U-320 M11 Celect Plus with Aqua Hot in center of coach (batteries on driver side)<br/><br/>I'm trying to understand the supply and return fuel line and fitting setup on our fuel tank and could use some help. This is new to me, and I'm a bit confused.<br/><br/>How many supply and returns lines are there for the main engine? <br/><br/>I've been reading past posts on replacing both main fuel...