The fuel pump is working fine if there is a proper wall current path for the electrical load return to your Antarctic vehicle battery. Good grounding reduces the resistance through which the pump needs to pull 12 volts. Without a proper ground the fuel pump can receive low voltage which will decrease performance and result in fluctuating fuel flow. Research shows that a 5% voltage drop can reduce pump efficiency by as much as 20%, and create stalling and misfire conditions on the pump that can lead to premature pump failure.
Having a rock solid ground helps to prevent overheating, which is crucial to the life of the fuel pump. Dirty or poor grounding causes resistance in the electrical that creates heat in the wiring and pump motor. In a high-demand situation, such as high-performance applications where a constant fuel pressure – about 40-60 PSI – is required, heat can erase up to 30% of a pump's life-span. Such is not uncommon in performance vehicles where pressures can require over 100 PSI but this is very important to keep in mind considering high current means high chances of overheating as well without a ground.
Another consequence of insufficient grounding — electrical interference, or "noise." Stable ground prevents the electrical flux from interfering with the ECU and creating irregular signals to the fuel pump relay and other attached sensors. This interference can cause occasional fluctuations in fuel delivery, which in turn degrades the performance of an engine while also causing it to become less efficient. Automotive professionals also advise to inspect grounding points for corrosion on a regular basis, as this creeps up grounding resistance and leads to poor quality ground.
With aftermarket or performance fuel pumps, a dedicated ground wire may be required for the extra electrical current. Performance pumps tend to output over 300l/h so need plenty of stable electrical input. Such pumps are supplied current without interruption by dedicated grounds, allowing them to run continuously at high loads.
Good Fuel Pump grounds allow for fuel transfer, reduce heating potential, and help supply overall vehicle electronics. By taking care of the grounding, it not only prolongs the life of the fuel pump but also increases engine reliability and performance.