Precision Power PCX 250 - Manual (Page 4)

Before beginning, disconnect the negative (-) terminal of the battery prior to
working on the positive (+) terminal to prevent a short to ground. This is important,
unless you want to spend the rest of your life with a nickname like
"Sparky," or
"Smokey." Reconnect the negative terminal only after all connections have been
made.
5
Warning! A Main Fuse must be installed within 18" of battery!
16