A #10 wire is a tad small for a charging wire. If you leave the lights on, a hard start and such will cause the alternator to pump more current into the battery than a #10 can handle. If it were mine, I'd install a #8 or larger. Problem is, your instructions are so bad that you are putting heavy current wire in places we don't normally see those connections. Example: one would normally run a high current wire from the alternator output to the large lug on the starter (if no amp meter is installed). Power connections to other places like lights are 'piggy backed' on to that large starter lug (hopefully through a fuse panel). In electrical lingo it becomes a 'buss'.
