In some vehicles, the starter is an exception to that. It is the highest draw item in the vehicle and can be bypassing the ammeter. You would have to check the factory wiring diagram to see how your should be wired.
To clarify, that statement should say "in MOST vehicles". The starter draws enough amps that it would smoke the typical ammeter, and possibly even melt the shunt that typically bypasses the ammeter.
What I'd do if you're running an ammeter is run a single power wire from the ammeter to your fuse block input bus, and distribute power to the various loads from there.
