[dsraven]

remember that the old trucks only really had a few lights, horn and a heater motor to worry about for load. if going with newer stuff and more accy then you should install a fuse/relay panel while you're doing the wiring.
relay-headlights, horn, heater motor, wiper motor if electric, engine fan if using that system, anything else that will draw a good load to run OR start up.
fuse-everything electric needs a fuse at the origin of the circuit in order to protect the wiring.
consider an alternator because they will keep up with the load at almost any engine speed. the generators are not meant for the higher loads of what most guys install for accy, plus they don't really charge at idle.
use the wire gauge according to the circuit max load. fuse accordingly