I did a whole lot of boat work before the depression hit here. I replaced many more combiners than I replaced isolators.
Adding and isolator to any truck no made for it will be a serious tear-up and it would void any warranty.
Are you sure it is an Isolator and not a Combiner?
In the years since, I have only seen one truck with an isolator. I have seen many with combiners. The combiners all have contacts. Those contacts fail. Isolators require that the main engine alternator have a remote sensing capability.
Matt