ok, so ground number 6 to the battery ...

 

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

 

Sounds like the small black wire with a green stripe at the NEG battery post has a bad connection or is not there.

 

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?

 

I also went thru the blink codes.. Came up with 87. 95. Primary and secondary fuel pump circuit failure

 

I'm sorry...my truck is a f450 with the 7.5 efi. Not sure if that's a game changer... But I was excited that grounding the pins made it run.. Like I said. 2 previous trips to shatty mechanics resulted in me towing the truck home ...

 

It should run from the NEG post of the battery to pins #40 & #60 of the EEC Computer.

 

Is this the same for 7.5? I'll check tomorrow to see if that's where it goes..

 

[QUOTE=cagedog;14498153]Is this the same for 7.5? I'll check tomorrow to see if that's where it goes..[/QUOTwhere is the EEC in the f-450? I know that's probably a dumb question ...but like I said...I'm no mechanic...lol

 

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 previously said pin 40 and 60.. But this doesn't show that many..lol. EEC case ground pin 20?? I have her tore apart now. And your help is much appreciated

 

OK..I'm sorry. Found pin 20-40-60. One is going to the fender for ground...the other 2 black wires with yellow stripe go into the harness.. I used my test light and grounded one end..probed with the other...and its lighting as if it has power ..

 

The wires going to pin #40 & #60 should never have power on them.
I up-dated the numbers in the above diagram for you.
By the way that is a green stripe, not yellow.
Case ground does go to the fender, #20.

 

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.!!

 

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.