bevjoe, perhaps we should ask you what your intention would be by using the "battery disconnect" switch?
As you can tell by the responses, there are two switches that might be found in a motorhome that can be considered "battery disconnect" switches. Until you can clarify and somebody with the same or similar coach as yours responds, we are all kind of guessing in our responses.
The most common and I'll go out on a limb to say it's the one that is referred to in your manual, is a switch that disconnects 12v power to the
house portion of the coach ...or what some have been referring to as the "salesman's switch."

There also can be a chassis battery disconnect. If you do have this switch (I going to guess you don't), it disconnects the starting (engine) battery so there is no parasitic draw when not in use.
For your house battery disconnect switch (until somebody with the same coach responds), look around the doorway area for a toggle switch, a red rotary switch, or some of the manufactures used the kind of switch pictured below in older RVs.
