Lately I have been running into a lot of older pumps that have trouble holding a prime with no air leaks or obstruction. I will prime them with forced flow from a hose and rag in the skimmer, they will seem to run ok, and then slowly lose prime over night. I dont have an amp meter and Im not sure what to look for if I get one. If i buy one am I just checking to see if the amp draw is higher than the runing amps listed on the motor plate? How much higher is ok? What does this higher amperage tell me? And finally, what is the cheapest amp meter that will function correctly? Thanks.