How to tell if fuel pumps are running by current draw?

current in the motor will drop, ONLY if the hot pump has an open circuit

a hot pump 'Stall' with out open circuit, will Increase current drain
and the pump motor will get hotter

unless it has an in motor temp over load AKA 'clik switch'

the ampmeter is the right idea

but better yet is to insulate the fuel lines, especially that big 'tin can' fuel filter

i'm ordering some 'Hot starter' shield wrap to insulate my fuel filter and external fuel pump