I think what ronaldjlee was saying is that he has a single #10 orange wire from the roof to a terminal block but is asking where is the negative/ground wire.
AFAIK most motorhomes use the frame as a negative/ground and maybe that is what they expect you to use. Not very good wiring practices IMHO. Frame grounds were abandoned decades ago on cars, although the aluminum frame makes a much better ground than steel.
David
Thor Forums
