From cactus and cartel land I cannot seem to find a wiring diagram for that vehicle. Would it be possible to contact an agency and ask the Service manager if both alternators are working in tandem? Alternator voltage regulators shut down in "Lag" situations. There is always an Alpha and Beta in a tandem hookup.
If the system is divorced, it may pay to do a feasibility study to determine if a 250-amp hairpin alternator would be a rational upgrade. This absolutely depends entirely on the question of dependence (or not) of using the vehicle charging system as a primary method of regaining fullness of charge.
The ratio time wise of loss of amp hours versus availability of AC available should not be ignored. Each 8-D has an initial charge acceptance of 200+ amperes. Quite an eyebrow raiser. For serious meaning prolonged bouts of generator recharging 300+ amperes of charger potential would not be irrational.
Some SMART charger's philosophy leaves me dumbfounded...
"Sir restaurant policy dictates we serve our coffee at 105F to absolutely preclude any possibility of litigation over the chance of scalding someone's lips"