We're all saying the same thing.
Electricians here call equipment that uses electricity "load."
So the load side of a device like a fuse box, or in this case the ammeter, is side with equipment that draws power.
The feed side of the same device is the side where the power is coming from.

The confusion with many cars is as you know, the battery can be both.
It is the power source when the alternator can not supply the power.
It is a load when it is recharging from the alternator.