1993 Sandpiper by Cobra

You probably won't find an owner's manual and if you did it wouldn't be much help. Owner's manuals for RVs are so generic they don't actually tell you much about your RV. If you have specific questions about plumbing, electrical, chassis, batteries etc, you'll probably have to do some research on the individual items and ask questions. The good news is that most RVs operate generally the same with the same appliances. Although your unit is a bit older, conceptually, they're all pretty much the same.