Try this. Create>CV Curve Tool. afeter you creat the CV curve whare and how you want your wire to go. Thin you Create>NurbsPrimitive>Circle. it will apear at the origen. you can scalle it to the size that you want your wire to be.. thin select the Nurbs Circle, ShiftSelect the CV Curve. Surfaces>Extrude (Box)
have your setings like what I have in the pic below. This will make your wire and you will not have to try to be tweeking all the CV points in the tube to get it how you like.

Hint. Put more CV points in the curved parts of the wire and less in the strait parts.. it will help the tube not pinch in the corners.

Hope this is what you were looking for.