Here are the
Body, Wiring Diagram and
Body, Wiring Installation diagrams for your coach. Here is the
Wiring Identification Guide . You'll notice that Winnebago labels every 12V wire every few inches, and you can look up those labels in the identification guide.
3 wires would imply a 3-way switch, paired with at least one other switch for the same function. Pages 3 and 4 of the Body wiring diagram show 2 three way switches for the Courtesy Lamps (footlights), each with 3 purple wires, labeled
NU,
PH, and
NY on one switch and
NU,
JE, and
NY on the other. You should also be able to look at the Body wiring installation diagram to identify where switches, etc. are located.