Nikita41987

Okay I've replaced my fuel pump two or three times I'm still having issues to where I'll be driving and then my car will completely either just shut off on me or it won't start at all it'll crank but it won't start I do know it's the fuel pump but it's the wires coming out of the top of my fuel pump I believe I have a wire ran from one of the wires out of my fuel pump directly to my power wire that is ran directly to my battery and when I connect those it'll start right back up but then my fuel pump will continue to run if I do not disconnect them and then I can't no longer use my amps or my sub so I'm wondering what could be causing this to do it because it doesn't do it all the time it's only sometimes it's like it's not the fuel pump's not getting power or it's shorting out due to the wires that are coming out of the top of my fuel pump. I do believe the wire coming out of the top of my fuel pump is blue that's the one that I have took in another wire and have connected to that one and then when my car does do this I've been take the other end I disconnected my power wire from my amp and then hooked that orange wire that I added to my power wire that goes directly to my battery and then my car will start right up but like I said I have to disconnect that from my power wire or my pump will continue to run which will burn it up I know that the main relay is good obviously my fuel pump is good it's been replaced two or three times so I'm not really sure as to what this could be or what could be causing it to lose power to the fuel pump here and there the fuses to my fuel pump are also good

tech8

The PCM (car's computer located under the center dash console) and the main relay (located under the driver's dash area) are used to supply power to the fuel pump. The power wire to the fuel pump normally come from the main relay. Curently you have it directly wired to power; thereby bypassing the main relay.

Sometimes the solder joints are bad in the main relay (the solder joint can be re-soldered) or there are some blown or leaking capacitors or bad resistors in the PCM (which can be replaced).

The PCM needs to supply the ground to the relay coil to energize the coil; so, that the relay contact closes to allow power to the fuel pump. How the mechanical relay works is (a) when relay coil is energized by power and ground then (b) the relay contacts close (think of it like a draw bridge) to power allowed through to the fuel pump

This is a circuit diagram of the fuel supply system where I added some notes and color coding. Red is positive and green is negative.