Help me understand my campervan split charge relay
Alternators (or any kind of electrical generator) work by providing a voltage between their terminals. The current provided by such alternator depends on what you connect to it (and the generated voltage, of course). The 90 A rating means you can draw at most 90 A without frying it, it does not mean that the generator is forcing 90 A through the circuit. So you can bet that if the relay and the fuse are not blowing, its because the current through them is below their rating. Hope that helps :)