Is there an inline fuse connected to the a/c knob lights on 2005 Toyota 4-Runner.

Just replaced the tiny little light bulbs behind the three knobs and they still won't totally
illuminate as they should. All I can get is light on the position tips of each knob but not the
function descriptions illuminated on the inner part of the knob. First off, can the three
bulbs go in the wrong way or will they ONLY go in the right way? Second off, might there
be an inline fuse associated with JUST these three tiny little bulbs that am not aware of
because ALL the other lights on the dash are burning brightly. Please help me out.