I put the bad machine's fuel pump in the good machine. No start, therefore bad fuel pump.
Not necessarily true, thats an assumption. A pump harness or plug problem could explain that. Rotten fuel jelled up in the pump can explain it, frozen water being in it, or a stuck bearing or bad armature can as well. You can put battery power directly to it while the pump is in your hand and see if that pump runs or is stuck.
You said your bike sat outdoors covered all winter. Those kinds of covered conditions can cause condensation & moisture buildup on everything... especially if it is hit by sunlight periodically and the sealed (by deep snow) cover is heated & cooled in cycles. I know all about that problem because I must live with it as well. A lot of my machines are tarped off year round, adding ventilation is the only way I survive those storage methods. Sometimes I lose the game though... and have to fix stuff that went bad or got corroded during storage.
That is why I suggested you take every plug apart on the bike... put eyeballs on them and plug them back in if they are not wet or corroded. Operate every switch relevant to your problem (in this case kill switch, Ign. switch, neutral/reverse/gear selection/indicator switches, etc.) looking for one of them to come back to life if it has been soaking wet & intermittently frozen solid for months. Measure voltages through the fuses themselves by putting a DC volt meter on each contact on top of every fuse. Check the diodes like the starting section of the service manual suggests. It is more likely an electrical failure causing your problem than a mechanical one... and going over everything routinely should reveal it eventually. The service manual shows how to test every switch and function and component on the bike... and you can direct test a few of them yourself once you get them off the bike.
What I was hoping to hear from experts was a little information on how the fuel pump gets its current. What components are key to making a fuel pump operate, and more specifically, which components, if not working properly, would prevent it from doing so? This is the knowledge I do not have, and trying to decode the wiring schematic in my manual makes me dizzy.
Yeah, wiring schematics can do that... LOL. But everything you are asking us for is in the service manual. You don't need to be looking at the wiring diagram just yet... read each section instead.
There are many, many things that can happen to make your bike quit like it did. If I sat here for an hour and listed everything I know about and could think of, I'd still miss half of the answers. This is a guessing game at best... its got to be diagnosed in an orderly fashion once most of the silly stuff is eliminated.
Unfortunately, with the bike sitting alone under a cover 1000s of miles away... its gonna be impossible to diagnose anything from home. At least you are armed with your most valuable resource though, having a printed copy of the FSM handy.
Go through the starting, ignition & fuel injection sections troubleshooting flow charts after you familiarize yourself with operations of each section. Certain things may or may not be mentioned in there... like the display for instance: the display is an integral electronic component for the fuel, ignition & starting circuits on that bike. If it fails, all kinds of bad (or weird) stuff can happen.
If there are any non-OEM electrical parts on the bike, suspect them, cause made in china means made to get your money, then fail. Likewise, if any of the harnesses have been spliced into, altered or fixed, suspect all of those hacks.
Do you have internet access and power in AK where the bike is located? If so, shout us up so we can help you when you get back there. If not, I dunno what to say... this is a guessing game at best, since you don't have the bike handy to work through any diagnostic steps. Hopefully its a silly problem caused by the tarp and not expensive to fix!
