Clock, Stereo, Wipers lose power

Just bought a 93 Altima, 136,000 miles. When I am driving the stereo, dash clock, and wipers will all of sudden lose power. Usually they will not work again until the car has been restarted. I do not have a guide to the fuse box, but figure the fuse must be good if it works at all. Any ideas?

Had a student suggest that I turn the key back just a bit when the power goes off. Turns out he was exactly right. Problem solved. Total cost= $0