I gotcha. Where in the midwest are you riding? I'm in mid Michigan. I finished my 72v nominal conversion in about August i think. Rode it through mid november. During those few months, I got caught in the rain a dozen times, at least 1 of those times was basically downpour. Clothes completely soaked through. 2-4 times when I parked at work in the morning, I noticed it was raining some time after it had started, so I went to cover up the motorcycle way too late, after a good soaking. So take my advice with a grain of salt, because I only have a few months worth of hands-on experience with this nature, but I do have a few pointers.
Waterproofing your individual connections is important for sure. But focus your attention not on whether wet environment will cause electrical shorts, but rather, whether water will collect in and on electrical components and not dry. If and when that happens, the connection fails. I believe both Great Scott and Electroboom on Youtube have run similar tests on basically dunking electronics in water. The danger isn't shorts, its eventual corrosion from water sitting on and corroding individual connections.
To that end, keep as many of your wirings and connections under some sort of shield. Use the interior of your headlight bucket for a lot of your connections, as is traditionally done with motorcycles anyway. Obviously for good reason. I hollowed out the original fuel tank, cut off the bottom, and stored my controller under it, so any water getting on the controller and all of it's connections would have to fight gravity from underneath, so I don't really worry about those. For connections that have to occur outside of an umbrella, try to use a loop or two, to force rainwater to the bottom of a loop and keep it from wicking upwards. For high current connections, I used solid copper lugs, and I put a healthy amount of dielectric great sandwiched between the lug and its connection terminal. My ammeter, voltmeter, and handlebar switches needed to be up and on the handlebars. To mitigate their demise, I basically gathered all of it and put it in a nice-ish box, mounted to the handlebars, and did a pretty good job of waterproofing that: screwed down onto a rubber seal, and all wires going in and out go through a hole at the bottom, to prevent sideways wicking. Are you using a hub motor? Pay attention to how the wires enter the axle, and seal it up better if necessary. Try to install it so that the wire port is facing downwards.
I dont have a pic of the handlebar box right now, cuz the bike is all packed up and disassembled for the winter. Which is my last advice. Chances are, your battery will either not be able to be used in the winter, or at least you wont want to ride a motorcycle exposed to the cold at those temps. So again I take a page out of the motorcyclist handbook, and plan to disassemble the bike quite a bit every year. Unplug everything once a year, inspect every electrical connection, check for rust and corrosion, replace what's necessary. Store important expensive components indoors for the winter. I keep the motorcycle under covered storage when parked at home, and I wouldn't be riding in rain anyway, but like you, I'm in the midwest, and getting rained on was going to be inevitable. So I spent quite some time planning and trying methods and revising, keeping my new bike alive in the rain was way at the top of my list of priorities. Let me know if you need any more specific advice.
