Rear fuel pump dead on 91 F250, cant figure out why
#17
I had same problem.. Grounded pin 6.. Which gave pumps power ..but they wouldn't prime the system..would only start with ether ..grounded pin 4.. It gave me power..primed the unit.. But the truck ran pretty rough...but did start onnits own... Grounded pin 2 (test out),,truck starts idles revs and seems to run great. But caused a check engine light.. What's the next step?,,I'm no mechanic. But seems like you guys are helpful and I've gotten further from reading than the last 2 mechanics... I'm going to be a pro now I've become a member...lol. Thanks for any help you can give
#18
I had same problem.. Grounded pin 6.. Which gave pumps power ..but they wouldn't prime the system..would only start with ether ..grounded pin 4.. It gave me power..primed the unit.. But the truck ran pretty rough...but did start onnits own... Grounded pin 2 (test out),,truck starts idles revs and seems to run great. But caused a check engine light.. What's the next step?,,I'm no mechanic. But seems like you guys are helpful and I've gotten further from reading than the last 2 mechanics... I'm going to be a pro now I've become a member...lol. Thanks for any help you can give
#19
Hmmm. The only black wire I see on NEG goes across the firewall to driver side then goes in the cab. Where should this black/green wire be going?
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Yes the wire should be the same, there should be a total of two small wires and one large wire. Left diagram below.
You might also want to run a 10GA wire from the NEG post to the Body (not the frame).
The EEC Computer is behind the the LH (drivers side) kick panel. It will unplug from under the hood and is removable from inside the cab.
Left diagram for a gas truck:
EEC Computer plug, 10mm wrench size bolt in in plug:
EEC Computer plug to show locations of pin 40 & 60 ground pins:
/
You might also want to run a 10GA wire from the NEG post to the Body (not the frame).
The EEC Computer is behind the the LH (drivers side) kick panel. It will unplug from under the hood and is removable from inside the cab.
Left diagram for a gas truck:
EEC Computer plug, 10mm wrench size bolt in in plug:
EEC Computer plug to show locations of pin 40 & 60 ground pins:
/
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You are the man!!! I found the culprit.. Thank you so much for your help!!!! There was a third ground wire that was broke off.. From the negative post there was a clip with 2 wires...one was broke...once again thank you tons!! Now to put it all back together.!!
#30
OK...so a few weeks back you guys helped me finding to issue described on this thread.. I used the truck a few times...worked great.. Its sat for a couple weeks..went to fire it up ..and once again no fuel pumps...I really needed to.move the truck so attempted to ground the pin on obd test plug to bypass...but now I'm getting nothing there either..all relays new..good grounds everywhere.. Bypass will not over ride?? Helppppp...lol.