The "50" pin of the starter (bosch term) - gets power from the key but routed through the neutral safety switch.

If the person saw no power at the solenoid trigger (point 50) while cranking then most probably the neutral safety switch is bad or the wiring has an open in it.

Its a purple/white wire, test it all the way - you should be seeing 12v +ve going into the NSS from the key in start position (test with a heavy lamp like a headlamp bulb to make sure full amps are going through)

in P or N the nss should be routing this same 12V +ve signal to the starter for it to spin.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)