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Electrical Fuel Pump Issue?

  • Thread starter Thread starter Eathon Chaney
  • Start date Start date Sep 16, 2017
  • Tags Tags
    ecm computer problems fuel pump wiring harness
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Eathon Chaney

New Member
Sep 16, 2017
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Sep 16, 2017
#1
  • Sep 16, 2017
  • #1
Alright so I've been across every corner of the internet and have finally broken down to make a forum post,I have recently gotten a 1995 Mustang,3.8l V6.

It has a brand new motor with only 30 miles on it and the whole front end has been completely put back together,by myself and two other mechanics (father and grandfather)

We are at a stalemate at the moment,there are two ground wires that plug in under the fuse box,and when we plug it in the ECRM starts making this whirring noise,and the fan consistently runs,but the fuel pump doesn't.

BUT if you unplug the ground wires the fuel pump turns back on,any ideas on what the issue could be?? We've ran a compression check on all six cylinders and have 150 PSI across all of them,so we know it's not a compression problem.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
Sep 18, 2017
#2
  • Sep 18, 2017
  • #2
I also found little info on the wiring for the 3.8 ccrm, do you have a repair manual like chilton?
Maybe a pic of the ground wires your working with?
 

jozsefsz

15 Year Member
Aug 11, 2013
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Cleveland OH Area
Sep 19, 2017
#3
  • Sep 19, 2017
  • #3
The fan shouldn't be consistently running. I'd approach those two mystery 'ground wires' with caution until you know what they are. The fan running, but the fuel pump failing to prime, is a symptom of the ECU losing its marbles (mine has done that with a corrupted tune). So you might be shorting out the ecu when you connect them. When they're disconnected, what's wrong with the car? Fuel pump priming, fan not running (until needed) sounds appropriate.
 

Christian Cornwell

Active Member
Aug 31, 2016
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Upstate NY
Oct 20, 2017
#4
  • Oct 20, 2017
  • #4
The wiring under the fuse box are both grounds. One is black and one is black and white if I remember correctly. On my car I went through and soldered them both together and ran a 8 gauge from. That to where the negitive on the battery connects by the headlight. I do have a 3.8 ccrm wiring diagram I'll try to remember to post up tonight when I get home.

I would also take the wire that is ground on the ccrm and ground that directly rather than making it go through the harness.
 
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