Alternator

To a certain extent, your chassis alternator output (voltage and current) is dependent on the current state of charge of your chassis battery(s) and the loads placed on the alternator by the VEHICLES electrical system. If your chassis battery is fully charged, expect the alternator output to be a fraction of it's maximum rated capacity until the existing loads drop the charge in the chassis battery. Ford engineers designed their charging system that way to improve fuel mileage and to prevent people from doing what they want to do . . . . . charge the batteries in their camper with the chassis alternator.

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