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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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Can someone help me with some wiring issues?

  • Thread starter Thread starter 68converted
  • Start date Start date Jun 2, 2008

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Jun 2, 2008
#1
  • Jun 2, 2008
  • #1
I did the 5.0 conversion using the motor, computer and harness out of a 91 GT Automatic. I have the A9P computer and per the Ford Dealership the computer is ok, and from the correct car. I am having trouble with the wiring, as the wire colors don't match the schematics. I don't have power to Pin 22, or to the fuel pump relay, but the computer does have power to it's relay.

Here is what I have: Blue/orange wire from pin 22 running out to the EEC test port, and back to a grey plug under the dash that carries the fog lights wiring (4 wires), a Tan/Yellow wire which runs back to the Fuel pump relay, and a red wire which joins a group/splice of about 5 red wires in the harness (this group includes the red wires from the ECU Relay- which do not have power with key on)

On the Fuel pump relay, I have the following wires: Red - 30 (runs back to the harness splice with the other red wires, Black/orange to 85, the tan/yellow wire from plug above to 87 and tan or grey/lt blue at 87a.

When the key is turned on (not start) I should have power to 30 but I don't. Can I just run a wire from 30 straight to the (+) on the Solenoid? Is there anything in the fuel pump relay circuit that is going to cause me issues, if I just isolate it, using the wire from pin 22 to switch the relay?

I just don't have any more money to spend to bring it to someone. Is there a wiring guru that can help me out? Thanks.
 

Vipersix

Founding Member
Feb 25, 2001
434
0
0
Clarksville, TN
Jun 3, 2008
#2
  • Jun 3, 2008
  • #2
Pin 22 should be tan/green running from the connector to the fuel pump relay and to the P1 on the self-test connector. With the key on, you should receive power through the EEC power relay via pin 37 and 57. Pin 30 is a signal wire from the transmission which ensures it is in neutral. The fuel pump relay itself gets power from the EEC power relay via the same wires (37 & 57) and connects to the pin immediately beside where pin 22 connects. It should not be connected to pin 30 in any fashion. There should be about five wires coming from the fuel pump relay, pin 22, pin 37/57, pin 19, pin 1, and the wire going to the pump itself.
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Jun 3, 2008
#3
  • Jun 3, 2008
  • #3
Vipersix said:
Pin 22 should be tan/green running from the connector to the fuel pump relay and to the P1 on the self-test connector. With the key on, you should receive power through the EEC power relay via pin 37 and 57. Pin 30 is a signal wire from the transmission which ensures it is in neutral. The fuel pump relay itself gets power from the EEC power relay via the same wires (37 & 57) and connects to the pin immediately beside where pin 22 connects. It should not be connected to pin 30 in any fashion. There should be about five wires coming from the fuel pump relay, pin 22, pin 37/57, pin 19, pin 1, and the wire going to the pump itself.
Click to expand...

This is great information. I believe that the harness is not one from a Mustang. I think it is from a Tbird. None of those wires match. I have confirmed with the dealership that the computer is definitely from a 91 Mustang, so I can use your information to "rewire" the relay.
 

Vipersix

Founding Member
Feb 25, 2001
434
0
0
Clarksville, TN
Jun 3, 2008
#4
  • Jun 3, 2008
  • #4
The '86-'93 T-Birds share pins 37 & 57 for keyed power, so that should help you a bit. Pins 20, 40 and 60 should all be ground, if you have the speed density version pin 49 will be as well. Once again, either way pin 30 will be the NDS signal wire.

Here's a great site which has numerous diagrams and schematics.
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Jun 3, 2008
#5
  • Jun 3, 2008
  • #5
Vipersix said:
The '86-'93 T-Birds share pins 37 & 57 for keyed power, so that should help you a bit. Pins 20, 40 and 60 should all be ground, if you have the speed density version pin 49 will be as well. Once again, either way pin 30 will be the NDS signal wire.

Here's a great site which has numerous diagrams and schematics.
Click to expand...

I have no idea what harness this is but I had a friend over to help me trace some of the wiring and not much of it matches. This is too much to mess with; I am going to have to find another harness somewhere. Any ideas?
 

Vipersix

Founding Member
Feb 25, 2001
434
0
0
Clarksville, TN
Jun 4, 2008
#6
  • Jun 4, 2008
  • #6
Junkyard! It's a gold mine half the time. Or you could try buying a new one but that will run you a few hundred dollars. I personally gave up entirely and put a whole new system in, to include the computer, so I could run my own wire.
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Jun 5, 2008
#7
  • Jun 5, 2008
  • #7
I decided to suck it up and just run new wires for the Fuel pump. Now I need to discover why I don't have power to the red wires of the ECC relay with keyed on.

I will go through the list of "no power" to figure that one out.

I'll probably have a ton more questions, so thank you for the help so far, and with whats to come!
 
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