24V DC to 5V for powering a Raspberry Pi 4 and a router for a vehicle - what should i use? DC/DC converter?
There are any number of 5V@4A DC-DC converters on the market.  I searched for &quot;4a DC DC converter&quot; and there were many possibilities.
You could also use a linear 5V 5A regulator but with a 24V input you'll have to have a heat sink to handle the power dissipated.