Printer Friendly Forum Posts - Voltage Drop Test Fuel Pump

Hey everybody,
I don't have a lot of experience working with electronics, but I do work on my own car all the time. This time I noticed my fuel pump felt like its going weak (even though I replaced it 6 months ago), and I know that voltage problems could cause the pump to run weak. So I did a voltage drop test, and the positive side came out 0.02V, but the negative is 1.58V. I figured that there is something wrong with the cables or connectors, so I traced the wiring from the pump and found that it goes to the fuel pump controller in the trunk, before going to the battery. I disconnected the controller and run a voltage drop again at that connector for the controller, and both positive and negative were about 0.02V. I went ahead and bought a new controller thinking it will fix the problem, but it didn't. So I separated all the wires from the connector for the controller (2 ground, 2 power, and 2 thin wires for some gauges) and only connected both ground wires to the controller. Running the voltage drop at the fuel pump after this showed good results around 0.02v, but as soon as I plug the power wire to the controller I get 1.58v of drop. Just to test things, I swapped the 2 ground wires, and with the power wire connected that gave me only 0.44v of drop on the negative side? I am very confused and I thought I could find some help from experienced electricians.