The passenger side alternator negative terminal connects to the back battery negative through the 12 volt diamond-shaped terminal block on the firewall near the brake master cylinder. Remember, the back battery negative is connected to the front battery positive.
The back battery positive goes to the top bus on the firewall, the positive terminal on the passenger alternator also connects to the top bus.
All alternator power connections are protected with fusible links except the negative drivers side which having no voltage over ground, needs no protection. Fusible links are nearest to the firewall on all alternator connections. Alternator power connections are 6 AWG, fusible links are 10 AWG with high temperature silicone insulation.
These wire gauges are minimally adequate for 100 amperes, I would recommend 4 AWG with 8 AWG fusible links if you have high loads like winch, snow plow or 1.5 kW inverter. In all cases, go with 24 volt consumers when available to spread the load over both alternators. A single 3/8" vee belt on a 2 inch sheave is at the limit for a 1.4 kW load. Most engineering texts would say that is a 1 horsepower limit, in the CUCV, it is over 2 HP with bearing and cooling fan load. This is why belts howl during low speed glow plug cycling. Either the belts squeal or the alternator main bearings wear out from excess belt tension. Notched belts help.
If you must rely on the system, a spare functional alternator is a great thing to have on hand. And a handful of alternator bearings with a full set of notched belts.
