yea the battery must be fully charged before hooking up to the battery tender.
thru-out the winter check the battery voltage. sometimes like mine voltage was way down so i had to 6amp chg the battery for a hr, then reconnected the tender.
I had to take my seat off to get to mine the first time. Theres a lead coming off the pos terminal with a fuse a few inches up the cable. Thats how i found mine. Ive talked to 4dealera and they all say its a factory install since like 2008 ish?