1986 Maxima w/ electrical problems -- no wipers, blower, or radio

[EurekaNJ]

Hi, I have a beloved 1986 Maxima (1/86, 4dr sedan, 6cyl) that is showing signs of age (the body will die before the engine does!). The latest issue is somewhat significant: the wipers, radio, and blowers all stopped working at once several weeks ago. I took out all of the fuses in the box to the left of the steering wheel and checked them out. They were all fine, but somehow the process of removing and replacing them fixed the problem and everything worked fine ... for another few weeks. Everything (wipers, radio, blowers) died again as I was driving and nothing that I've done with the fuses have made them come back. Other lights/interior features work fine, but clearly wipers are kinda essential. Does anyone know of something in the wiring that could cause all three things to stop working at once? Many thanks!