wiring mishaps have damaged in the dimmer/---------- illuminator?
they are easy to blow, apparently.
and once gone, there is no flow of electricity thru it.
i would look for the part at opposedforces.com/parts.
i think it is located under the dash, looks like a relay????
because of the screw in the pic, it may be mounted on the removable panel below the steering wheel.
item #5 below: