The reverse light sensor won't cause the car to not start but the PNP switch will. The PNP switch detects a ground when the transmission is out of gear and allows you to start the car. If it's in gear it needs to see a ground from the switch on the back of the clutch pedal before it will allow you to start the car.
neither of my cars have those plugged in.. my dumb ass or some other dumb ass broke the damn plug or pulled the wire out of the sensor oorrr time killed em.. idk .. but tell u what my cars start dont they dan lol