Mike,
I had similar problem on my '96 E38 and it wasn't fuses, breakers or motors. It was corroded terminals on the wiper relay connector. Enough water had got to them to shut down wiper function.
Fix was to have the contacts cleaned and reconnected. Problem is the location -- they're way down toward the bottom of the E-box, the assembly under the hood at the rear on the passenger side. Take the cover off and you'll see circuit boards and bundles of wires. Under them are relays, including ABS and wipers. It's a lot of effort to get those pieces out of the way. Then it's standing on your head to do the work in a confined space -- not easy at all.
There's a hole at the bottom of this E-box that's supposed to drain, but mine had stopped up enough that water couldn't get out fast enough, allowing the corrosion.
Your problem, of course, might be something else.
Jim