I recently had my fuel pump replaced after a side of the road failure on my Super duty e450 RV. The mechanic was able to knock on the gas tank several times to revive the pump. He then told me that this is indicative of a failing pump, so I had him replace it. I drove home another 300 miles and was able to use the vehicle for a month or so before storing it. When I went to start the motor after the vehicle was stored for about a month, the exact same symptom of fuel starvation repeated itself. I checked fuse, replaced relay with another identical one, and also replaced relay control board, all of which did not fix the problem. I did keep the used fuel pump that was replaced and connected 6V dc to it to confirm the motor worked. I then found the plug for the fuel pump, disconnected it and reconnected the old fuel pump just to see if the problem was in the newly replaced pump or in the signals present at the pump connector. The old pump did not start. This convinced me that the new pump is not the problem. I would like to know what voltage I should be reading at the fuel pump connector pins. I measured no voltage on what I think are the pins that supply voltage to the pump (pink/white wire and black wire), and I read 12 v across two pins, even with the motor off.
Can any one supply me with a wiring diagram, or a description of the fuel pump connector pins and what voltages should be measured when engine is off and then when the key is turned on to first position before start? The four wire colors I have on the 2006 super duty are pink/black, black, yellow/white, and grey.
Thank you for any help!