Assuming the bike still has the original flasher, ground terminal 31, apply 12V to terminal 49 (brown/black) wire. the remaining terminal (terminal 49 purple wire) needs to go through a load (bulb or resister will do) the relay should click. Or you could go the easy route. Any cheap automotive 3 prong relay will work with the stock signals, just go buy one.
Thanks Howie! It's the original flasher. I'll try running a current through it as per your suggestion. That said, I'll probably just end up at NAPA and spend the $10 on a new one anyway.
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Edit: I just picked up a generic 3-prong flasher from Canadian Tire, plugged it in, and it worked. Thanks for the help!