question on bulkhead connector bypass

When I troubleshoot charging problems (for example) I tend to group the system into "sections" more or less

1...You have the main charging circuit This is what the MAD bypass does.......improves that high amperage circuit. This is the black charging wire through the bulkhead, through the ammeter, out the red wire and back out the bulkhead to the battery. Not only is the wiring too small for modern higher amp alternators, the connections at the bulkhead connector are not adequate, the ammeter itself can have problems, and in rare cases, the welded splice can fail

2...The field/ VR circuit. This circuit, too has problems. Voltage drop in the ignition switch and connector, the bulkhead terminals, the VR connector on newer cars, and problems with the alternator brushes

3....The ground circuit. Interconnections between the battery, body, engine (alternator) and VR

4....The main components, the battery, VR and alternator

The entire system is/ can become a "loop." The VR senses battery voltage through the ignition circuit, AND THIS MUST be "close to same as" battery voltage to work properly. The VR adjusts field current to cause the alternator voltage to rise or fall until "the loop" is satisfied that the voltagel is at the VR set point.

THE ONLY TIME this situation is not "true" is something like an aftermarket "one wire" setup which senses voltage right at the alternator output. post