in the case of some vehicles........mostly gm and ford trucks....you need only know the wire color that feeds 12v to the pump. the connector's usually fairly easy to access. of course the relay's the best option.
I know which relay is the fuel pump on all my cars, and have the quick disconnect tools needed, plus the appropriate size hoses.
one of these days I'll get the matching barbs, so I can just push it into the fuel line and have a guaranteed leak free connection.
Here's some really useful pandemic tips from down under. So to speak.
NSW Government Says Avoid Sex During COVID, Instead Masturbate in Front of Your Partner While Social Distancing, Wear a Mask · Caldron Pool