I have a 1991 Ford F150 6 cyl. 4x4 sh. bd..
I am not getting any power to my fuel pumps. Here is what I have tried so far.
1. Checked all fuses (fine)
2. Disconnected the fuel lines from both tanks. Tried cranking the engine and the pumps are not pumping.
3. Replaced the fuel pump relay with a new one. ( no change)
4. Repalced the EEC relay with a new one. (no change)
5. Checked the connection on top of the front tank. (fine)
5a. Checked the wire harness with a volt meter. There is no reading for volts at all. The ground is working fine.
6. Checked the inertia swich. (it was not tripped.) Also just checked it with a ohm meter. (Switch checks out fine).
6a. Did a volt check at the wires for the inertia switch with (koeo).
green w/ yellow stripe = 6 volts
red w/ yellow stripe = 0 volts
7. Hooked up an exterior in line fuel pump with a hose shoved in the fuel tank. (truck runs fine like this.) Pump was installed just after the in line filter.
8. I just checked the wires on the fuel relay plug. This is with the (koeo) key on engine off.
RED = 12volts
yellow = 1 volt
green w/ yellow stripe = 6volts
green w/ red stripe = ground
9. Voltage check on the EEC plug
yellow = 12 volts
red = 2 1/2 - 3 volts
10. I have now cleaned all the connectors on the fender area and reconnected with a conductive grease.

Now I am out of things to check. What would be my next item?
Thanks in advance for the info, Nels


Heading out to check the connection just mentioned.
a. Didn't find the connection listed on the post below. I did follow the wire harness up to the front left fender. It splits into 3 connectors at that point.
I have now cleaned all the connectors on the fender area and reconnected with a conductive grease.

Look at the electrical connector inside the left frame rail near the left front axle radius rod bracket. That is a very common place to have corrosion problems, and a very common place to lose power to the pumps.

Did you check the fuel pump cut off? Look in the owners manual and see if you have one. Sometimes they are located on the passenger side behind teh kick panel. Just push the red plunger back down if it is popped up.

check the fuel seleter switch

I have a 1991 Ford F150 6 cyl. 4x4 sh. bd..
I am not getting any power to my fuel pumps. Here is what I have tried so far.
1. Checked all fuses (fine)
2. Disconnected the fuel lines from both tanks. Tried cranking the engine and the pumps are not pumping.
3. Replaced the fuel pump relay with a new one. ( no change)
4. Repalced the EEC relay with a new one. (no change)
5. Checked the connection on top of the front tank. (fine)
5a. Checked the wire harness with a volt meter. There is no reading for volts at all. The ground is working fine.
6. Checked the inertia swich. (it was not tripped.) Also just checked it with a ohm meter. (Switch checks out fine).
6a. Did a volt check at the wires for the inertia switch with (koeo).
green w/ yellow stripe = 6 volts
red w/ yellow stripe = 0 volts
7. Hooked up an exterior in line fuel pump with a hose shoved in the fuel tank. (truck runs fine like this.) Pump was installed just after the in line filter.
8. I just checked the wires on the fuel relay plug. This is with the (koeo) key on engine off.
RED = 12volts
yellow = 1 volt
green w/ yellow stripe = 6volts
green w/ red stripe = ground
9. Voltage check on the EEC plug
yellow = 12 volts
red = 2 1/2 - 3 volts
10. I have now cleaned all the connectors on the fender area and reconnected with a conductive grease.

Now I am out of things to check. What would be my next item?
Thanks in advance for the info, Nels


Heading out to check the connection just mentioned.
a. Didn't find the connection listed on the post below. I did follow the wire harness up to the front left fender. It splits into 3 connectors at that point.
I have now cleaned all the connectors on the fender area and reconnected with a conductive grease.



maybe a fuse...??? :rolleyes:

check the fuel pump relay can you hear it click when you turn the key to on pos.

Look at the electrical connector inside the left frame rail near the left front axle radius rod bracket. That is a very common place to have corrosion problems, and a very common place to lose power to the pumps.
which connector are you talking about,the connector at the external fuel pump on the frame or another?

I have a 1991 Ford F150 6 cyl. 4x4 sh. bd..
I am not getting any power to my fuel pumps. Here is what I have tried so far.
1. Checked all fuses (fine)
2. Disconnected the fuel lines from both tanks. Tried cranking the engine and the pumps are not pumping.
3. Replaced the fuel pump relay with a new one. ( no change)
4. Repalced the EEC relay with a new one. (no change)
5. Checked the connection on top of the front tank. (fine)
5a. Checked the wire harness with a volt meter. There is no reading for volts at all. The ground is working fine.
6. Checked the inertia swich. (it was not tripped.) Also just checked it with a ohm meter. (Switch checks out fine).
6a. Did a volt check at the wires for the inertia switch with (koeo).
green w/ yellow stripe = 6 volts
red w/ yellow stripe = 0 volts
7. Hooked up an exterior in line fuel pump with a hose shoved in the fuel tank. (truck runs fine like this.) Pump was installed just after the in line filter.

8. I just checked the wires on the fuel relay plug. This is with the (koeo) key on engine off.
RED = 12volts
yellow = 1 volt
green w/ yellow stripe = 6volts
green w/ red stripe = ground
9. Voltage check on the EEC plug
yellow = 12 volts
red = 2 1/2 - 3 volts
10. I have now cleaned all the connectors on the fender area and reconnected with a conductive grease.

Now I am out of things to check. What would be my next item?
Thanks in advance for the info, Nels


Heading out to check the connection just mentioned.
a. Didn't find the connection listed on the post below. I did follow the wire harness up to the front left fender. It splits into 3 connectors at that point.
I have now cleaned all the connectors on the fender area and reconnected with a conductive grease.
have you found or fixed the problem with the fuel problem.i have checked and changed everything as well and still nothing

i know this soudns stupid but have u checked the tank selector switch?

maybe a fuse...??? :rolleyes:
i have a ford 150 4x4 with 2 fuel tanks i had the same problem the pump hanger is the prob. the stud on the top of the tank on the hanger will get conection but not in the tank i was told to replace the hanger but it cost to much so i cleand it and sodered the conections back to gether try that it might be your prob.

pump hanger has no conection from top to bottem