The trouble is Shawn there are several different type of split charge relays, each with a different set up, when you buy you S.C.R. they will come with a wiring diagram.
If your really unsure about wiring one, get an auto electrician to install it for you, it doesn't cost that much, and
its a lot safer. or when you buy it and your still unsure post the instuctions on here and we see what we can do for you.