My pump only pumps for a few minutes and then stops. What is happening? Generally "short cycling" indicates the motor is drawing too much current from the power source for some reason, and the thermal relay is opening to protect the insulation from the resulting heat build up. If this is what is happening the thermal relay will reset after 10 to 20 minutes and the motor will again operate. The causes of too high a current in this pump design are few and generally related to a motor defect such as a binding pump or motor bearing or shorted motor windings. See the Troubleshooting Guide in your Owner's Manual packed with your unit or the copy available in the Reference Documents section of this More Info page for things to check. The oil in the pump appears milky. Is there a problem? The oil in the motor gear box should always appear clear and clean. A milky appearance or a change in color or appearance of this oil virtually always indicates a leak has developed and the pumped fluid is contaminating the oil. Drain the oil and thoroughly flush the gear box with clean kerosene. Locate and repair the leak. Replace the lubricating oil with approximately 16 ounces of a SAE 30W motor oil before returning the pump to service. See the Troubleshooting Guide in your Owner's Manual packed with your unit or the copy available in the Reference Documents section of this More Info page for more details on these procedures. Why do I have to use the heavy wire supplied with the DC pump for connection to my battery? Your pump is a commercial grade unit and as such draws a high current from your battery to do the work required. If that current were routed through a light wire, heating and possible damage of the wire, and reduced voltage at the pump would be the result. The wire supplied with your pump is sized to provide that optimum performance you demand and the pump can provide if properly installed. It is also recommended a 30 amp slow blow fuse be installed in the power line to insure safety, should a short circuit develop in the pump wiring. Although the pump draws much less in normal operation, motor starting currents are significantly higher, necessitating the higher rating on the fuse.