a guess would be that over a prolonged period of time the extra heat build up has [slowly] taxed your wiring and [hopefully not] part of your electrical system.
i am not a professional tech.
can you have your mechanic look at it or if the car is a keeper maybe m.b. check it out.
i used to run 80/100 watt h4 bulbs, 9 months. i got paranoid and cut back, just to be safe.
*92 400e 124.034, SOLD
*92 300e 124.030, SOLD