What model Lacrosse? Bypass valve in 2010 303RKS behind panel under right side of sink, can be reached somewhat without removing panels, better to remove side panel that divides left and right under sink. Valves and pump are right next to water heater. I use air method of winterizing and put just enough anti freeze in fresh water to go thru pump, so I do not use the valves, just my method, use what is good for you.
2006 Silverado 2500HD Duramax
2010 Prime Time Lacrosse 303RKS
2007 Hensley Arrow Hitch
PT Crew Member 125
Good Sam Club, Cedar Creek Sams Chapter
Passport America Member