1993 Ford Explorer (5 Speed) randomly cuts off while driving

If you replace your power steering pump has noting to do if your car die
if you have a problem whit your power steering system the only symptom you will have is a real hard steering wheel.

if your car randomly die may be a false contact on your crankshaft position sensor.

is located next to the crankshaft pulley (harmonic balancer)
tray unplugging it and cleaning the terminals whit electrical contact cleaner (sale on auto part stores) and if is to rusty you may have to change the sensor or the wire plug.

NOTE is CRANKSHAFT sensor not Camshaft they sound a like.

it may be a good idea to get you car scanned for trouble codes
most auto part stores do it at no charge.