Radio display panels are "generic", and are used in several makes/brands of radios; Ford, GM, Dodge, and many other automobile manufactures. Based on the electronic circuit of the physical radio (and other electronic circuits that may feed into the radio), various icon displays are lit to indicate various functions. So in short, just because you can "see" it in the display, does not mean the automobile manufacturer designed an electical circuit to light up that icon in the display.
If automobile radio schematics are still sold (used to be sold as "Sams photofacs") for modern day radios, you could figure out a way to lit up a particular icon in the radio display by some other switched function, such as the fan switch lighting up the radio's fan icon whenever the fan is activated.
Whould require some study of the radio's schematic to see what circuit activates (lights) the icon in it's display, then activating that "lead" with an input made by you.
It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.