you have to get used to learn about basics
in electrics and soldering. That are cars with an age >15 years old. BUT, the good thing is they are still repairable DIY and no black boxes.
See my website below and you find all necessary information for DIY. In this case it might be just some bad contact, so maybe some good contact cleaner spray will do, or bad ground wires there, or the bulbs have to be changed, or the interior light dimmer is on the way out, or the fuse is not good or has some bad contact. Easy stuff.
SHOGUN'S TRICKS AND TIPS FOR THE SEVEN SERIESShogun E32 Tech Tips: http://twrite.org/shogunnew/topmenu.html