prewiring for vent fan -- wire colors

[RicoV]

Hi,
I have a 2011 Grandby with a roof vent that contains adjacent prewiring for an optional fan addition. One wire is yellow and the other wire is black. Can someone tell me which is the positive (hot) wire? This may seem to be a silly question, but the FV 4000R fan I'm ready to install uses black as its hot lead and white as its ground, so I just have to ask... Thanks!
RicoV

 

[jbahr]

Black is negative, yellow is positive.

Camper yellow (+) to fan black (+)
Camper black (-) to fan white (-)

 

[RicoV]

Thanks much, Jason.