Dads right .. It will run on the alternator .. I too have done this for years ..
But.. it won't run well .. and .. you have to keep the rpms up .. if they drop for an instant .. it will die .... but it will tell you if your system is charging ..

Zip .. you're not blowing fuses .. so I doubt that you have a short ..
If you have a bad alternator .. the bike will act as you say .. as drains the last ounce of life from your battery .. then dies..

I would do the "shade tree" check to the alternator as Dad outlined .. then check your battery..

Build it the way you want it ..... then learn how to ride it like you own it..
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