Electricity isn't hard to understand. If you think of it needing a circle or circuit to work then you have it half whipped.
Electricity flows out from a power source, to a switch to control the flow, to the item or load you want to operate then back to the power source.
Like with your wiring, power flows out of the battery to a 20 amp fuse to the main switch, from the main switch to the fuses. On one fuse power flows out to the headlight switch, to the dimmer switch, to the headlight and from the headlight to ground that leads back to the battery. Thats a circle or circuit
Power to switch, to coils to points to ground, another circuit.
Every circuit needs a power source to a switch to a load to ground.
A fuse between the switch and power source is a good idea. Some circuits with small individual current draws can be hooked to the same fuse.
I have the ignition on it's own fuse. The turn signals and brake lights on a fuse. The head/tail lights on a fuse. A fuse feeds power to the reg/rec and brushes. One for the horn. I guess the horn could go on with something else, like the turnsignals and brake lights.
I think you can see the point. Each circuit using it's own fuse, if a problem occurs you can find the problem quicker and on the road side you can swap a fuse from a less important circuit to a more important one. LIke from the turn signals to the headlight in the middle of the night.
Section 8 on your meter when testing a low ohm device, as in the rotor or stator. Before you test touch the probes together, this reading is just the leads, Now when you do the test subtract the leads ohms from the test ohms to get the actual reading. My HF meter reads .8 ohms today, it can vary some + or - some. When I test a rotor and get say 6 ohms I subtract the .8 and get 5.2 which is fine. If I didn't do the leads check I might think the rotor a problem an spend money I didn't need to.
Even on days my HF meter reads 1.5 ohms on the leads it still checks the rotor ok.
I have $40+ Sun Pro meter that has better leads they ony read .1 off. Both meters get a good reading, just have to use different numbers when subtracting.
On higher ohm reading the subtracting isn't nessary. Once you get up to 50 ohms or so the leads are well with in the tolerances of most things you test.
Most things are 10% or more tolerance. 10% of 50 is 5, so .8 is well inside that. About 1.6%.
Leo
Leo