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Tim Mohr
Tim Mohr, ASE MASTER TECH
Category: Ford
Satisfied Customers: 15121
Experience:  30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL
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I have a 2012 F250 that Wont Power the 4th Prong to turn on

Customer Question

Hello I have a 2012 F250 that Wont Power the 4th Prong to turn on the fuel pump. If i jump the FP relay everything works as intended
Submitted: 1 year ago.
Category: Ford
Expert:  Tim Mohr replied 1 year ago.

Hi, my name is ***** ***** the fuel pump removed, how many prongs have power, when cranking?

Customer: replied 1 year ago.
With the relay removed?
Expert:  Tim Mohr replied 1 year ago.

yes, probe the pins in the socket and see if 2 of the pins have power, when cranking,Tim

Customer: replied 1 year ago.
here is the the Schematic im using so we are on the same page.. Pins 1/3 have battery power , Pin 2 has 12 volts with key on pin 4 needs 12 volts but is not receiving it
Expert:  Tim Mohr replied 1 year ago.

that scematic shows pins 1,2 3 and 5????

Customer: replied 1 year ago.
sorry
Pin 5 should be powered with koeo
Expert:  Tim Mohr replied 1 year ago.

No, pin 5 should be grounded, from the PCM, not powered, it grounds that pin to activate the relay and send power to the fuel pump, but also pin 2 should not have power on it????

Customer: replied 1 year ago.
with koeo why wouldnt it have power on pin 2??? according to pin 1 its hot at all times then when you flip the key on you get should have power to pin 2
Expert:  Tim Mohr replied 1 year ago.

the pins 1 and 3 have power, then when you turn the key on, pin 5 gets a ground from the PCM, which then activats the relay and it sends power to the fuel pump through pin 2, but pin 2 nshould not have power with the relay removed, at any time

Customer: replied 1 year ago.
lol let me try this again ....Koeo , Relay in Place
Pin 1= B volts
Pin 2 = B Volts
Pin 3= B volts
Pin 4 = 2.00 volts
When it should have a 12v ground
Customer: replied 1 year ago.
Koeo, Relay OutPin1 b volts
Pin 3 b volts
Pin 2 0 volts
Pin 5 0 volts
Expert:  Tim Mohr replied 1 year ago.

ok, so with the relay installed, and the ke on, then you have power on the pin 2?

Customer: replied 1 year ago.
i have B volts at pin 2
Expert:  Tim Mohr replied 1 year ago.

then the fuel pump should run, the relay is working the way its suppose too??? what did you jumper to get the fuel pump to run? the pins 1 and 2?

Customer: replied 1 year ago.
I jumped Pins 3/5 To Close the switch and the vehicle will start and run with the pulse width modulation its supposed to have commanded by the ECM to the FPCM and with my meter inline gives me a min/max reading i can watch it pulse from 9v to b volts. Relay is a good relay. i have tested it with my relay buddy that i have
Customer: replied 1 year ago.
there are currently NO DTC's from the IDS program we use
Expert:  Tim Mohr replied 1 year ago.

3 and five are the coil controls for the relay, so you most likely dont have a ground on the pin 5, can you check the pin five for a ground, with the key on and relay out?

Customer: replied 1 year ago.
yeap gimme a few
Expert:  Tim Mohr replied 1 year ago.

let me know,Tim

Expert:  Tim Mohr replied 1 year ago.

did you check this pin for a ground?

Customer: replied 1 year ago.
havent had time yet i got swapped to a different job i will let you know tomorrow if thats ok
Expert:  Tim Mohr replied 1 year ago.

let me know,Tim

Customer: replied 1 year ago.
Hey Tim. I got it figured out pin 2 wire was broke by the body control module
Expert:  Tim Mohr replied 1 year ago.

one of them was for the Pin 5 wire, wasnt it?

Customer: replied 1 year ago.
No it was the ground on pin 2 after the wire came our of the bcm
Expert:  Tim Mohr replied 1 year ago.

pin 2 that goes out to the pump???