my 2012 fleetwood motorhome ford v10 keeps losing coolant from bottle.

Slight leakage is hard to find, sometimes even bigger and large discharge. Such as table there is a heater tank, sometimes slightly leakage is difficult to find sleep. Such as cylinder pad or cylinder internal mild water seepage is hard to find. Or patient slowly find leakage, or that first open, and serious to find, easy to some. The lid of the water changed yet? Sometimes the things slight leakage, a very cheap. Try this web you can www.hobd2.com

should be under warranty still but poss cracked coolant bottle. very common

This is a complex problem, I suggest you to have a look at http://www.obd2life.com and find some useful car tool for you.