Aerator

Could be bad panel or bad ground on the terminal block on the transom. Just test the new pump first by touching the + and- directly to the battery to make sure it spins. If it does it’s the block or panel.. Clean connectors on the block and try again. Still don’t work after that it’s probably the panel.

Sorry, though the aerator may run without a circuit protector (fuse) and still be bad. The directions are partially right in that you need to check the terminal block and connections. Swap wires from a bilge to the aerator and see if it functions. That will run through the panel and then you can track the issue.