Would the diode and the fuse protect the other components if power wiring is reversed?
Under normal operating conditions the diode D3 is reverse biased with only a small leakage current passing through it.

If the input polarity is reversed the diode will conduct to minimize the voltage and protect the following circuitry.

The forward voltage will depend upon the current available from the source - it could be about 1V at 30A. The following circuitry would probably not be damaged with only 1v of reverse voltage. The fuse needs to be rated to blow within a short time at this current.



SS24 Datasheet