Post a picture of your multimeter face. Most all of them have a black lead and a red lead.
Perhaps the root is that you don't want to work on it? Just asking. Not everyone wants to learn a new skill.
I can tailor instructions to most anyone that wants to learn or has the will to get it fixed. It seems like a trained person should be able to track down a problem, even if it isn't a Suzuki.
The first step is problem verification/definition. "It's broke" doesn't relay much information beside personal dissatisfaction. However, reported voltage numbers begin to tell a story.
Have you fully charged the battery, via a separate charger? Measured what happens to it when the engine is running?
If the wiring is not stock and no one has an accurate wire diagram for it, it's going to take intimate knowledge of your unique bike to effect a repair. Not even general instructions may apply if they reference wires or wire colors you don't have. I can tell you bit by bit what has to happen in each part of the circuit. But, that is a lot of info, and much of it won't be necessary. Troubleshooting is a progressive affair, when one bit of information leads to the next query, and so on, until it is either fixed or you know some portion of the system isn't doing what it should. None of us are going to be able to wave our hands and say look at this broken bit, without some information to go on. Shorting out the battery is tantamount to throwing a wrench into the crankcase while it is running. You aren't going to fix it before at least looking at it, taking some measurements, and comparing those to known good components.
Basic electricity is not hard to understand if you have the will. Short of that, if you can follow instructions, and relay information gathered, we can get you going again. There just isn't that much to it, really.
Cheers,
