grounding question re: the neg battery cable

I said no10 only because this is what the older factory stuff used. I should have said that "bigger the better."

All loads in the car except ignition are grounded to the body/ frame, not the block. This means a good connection from the block to frame is important.

The regulator only can control "what it sees." One of my favorite posts is to have guys check their regulator wiring BEFORE they replace a regulator that may not be bad

The regulator is bolted to the body, so if it's not the same voltage as the battery negative, the battery will be running "too high." Same deal on the voltage TO the regulator, from the key, ---here's the deal

The ground path from the battery negative post---through the cable to the block--through the extra ground from block to body--to the regulator mount.

All this can add up to "voltage drop," a tenth of a volt here, a hundredth or two there. When all's done, the regulator may be "above ground" from the battery negative post. The charging voltage INCREASES at the battery by this amount of drop

The SAME is true of the drop on the positive side. Here, the path is from the battery--through the cable--to the big stud on the starter relay--fuse link--through the bulkhead connector--through the ammeter--to the connector at the igntion switch,--THROUGH the switch contacts, --BACK out the switch connector, --BACK through the bulkhead connector, and finally to the "dark blue" ignition run wire in the engine bay, which feeds the ignition, the alternator field on '70--later cars, the REGULATOR ign terminal, and the electric choke if used.

SO THIS PATH has a lot of places to lose voltage, including the bulkhead connector, (twice) the ignition switch connector, (twice) the switch itself, and any other poor connections along the way.

So if this voltage is say, "trying to be" 1/2 or more volt LOW by the time it gets to the regulator, the regulator just jacks it up UNTIL it's at the regulator setpoint, say, 14.2 AT THE IGN TERMINAL. But the CHARGING VOLTAGE at the battery IS NOT 14.2, because of the voltage drop in the harness. You ADD the setpoint (example 14.2) to the voltage drop, say 1/2 volt, and now the charging voltage at the battery is now up to 14.7, and I didn't include the drop in the ground side, which will add whatever drop is in the ground circuit.