N,
Very good .. you would make a good diagnostic tech , vs a parts changer.
You can easily now see why I recommend starting at the 12v feed spot in the circuit... this is the perfect mid-point for diagnosis as it is where the switching controls and the actual starter circuit meet.. it is also where the cabin and engine compartment wiring seperate..
Backwards is always the simple route.. for guys who don't understand electric circuits , I often tell them to think 'Plumbing". where the wires are just pipes, with shut off valves and water feeds .. makes the basic concept look much less confusing..
... If there is one good thing about the CDs, [ probably the only one] . it is the schematics...with those, a test lamp and a jumper wire , you can trace most simple series circuits/systems out pretty well... another trick is to print the schematic out and use a High-Liner pen for tracing that particular circuit,,don't get your wires crossed that way, as there are a ton of them...