Mustang 5.0 Wire diagram | Ford Explorer Forums - Serious Explorations

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Mustang 5.0 Wire diagram

Can anybody scan me a picture of some connectors and their application on the stock Mustang wiring harness. (1990 Mustang 5.0 Computer Harness)
-More specifically: The Green Plug near the computer, and the black and gray plug in the engine compartment.

(I have the Ford Mtorsport Multiport EFI 5.0 wiring diagrams, but the colors dont match up) The engine and all the wiring is in the explorer, and ready to be fired up!

Al -

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I ran into a problem, when converting my Ranger to 5.0, with the connectors by the computer but I do not remember what exactly it was.
I contacted Ford and they straightened it out.
Did you get the Ford EFI Conversion Wiring Manual from Ford Motor Sport ?

If not I found my copy and will scan to a word document if needed.

I have the Ford Motorsport Multiport EFI 5.0 wiring book. Although, I have a 1990 stang harness. It is not the same as the Ford Motorsport harness. (the wires dont match up, and their are extra plugs)

specifically the Gray and black plug.......instead of one grey plug...

By the way: Does the 4 plug transmission wiring go in to the stang Computer harness, or the Explorer body harness?


In the Ford manual is a number to call for conversion info, Try it.

In the mean time I will try to see what I did.

The 4 wire plug for the tranny goes to a plug on the left whell well shield. This plug has the reverse light, oil pressure, water temp and neutral saftey wireing all in it.

Here is a pic of the plugs I am talking about. Can anybody with a mustang "hemls" manual, tell me their wire color codes and functions?Dead Link Removed

Is this on the passenger or drivers side of the engine compartment?

here you are
Grey plug(lock clip up male)

1 2 3 4
5 6 7 8

1- PK/BLK- fuel pump relay +12v

2- blank


4- RED/WHT- water temperature sensor

5- ORN/YEL- speed sensor

6- GRN/WHT- speed sensor


8- WHT/RED- oil pressure sensor

Black plug same set up

1- Blank

2- GRN/YEL- tach signal

3- blank

4- blank

5- RED/LT GRN- +12v switched power (ecm switched power)

6- RED/BLU- +12v neutral safety switch start signal

7- GRN/PNK- A/C relay power

8- WHT/PNK- low oil sensor signal from oil pan

Thanks you very Much!! thats exactly what I was looking for!!!!! You must have a Helms Manual for the mustang?? What about that green rectangular plug near the EEC? (color codes do NOT match Ford EFI managment book)


Green plug

same as before (tabs to left plug)

1- TAN- check engine light

2- blank

3- BLK/WHT- sensor signal return ( to clutch sensor on Mustang)

4- blank

5- RED- +12v switched power to sensors and computer

6-TAN/GRN- -12v fuel pump relay trigger


8- GRY/YEL - +12v switched, fused power to HEGO sensors.

Sorry about the time it took to answer. I hope this will help.

I use an combination of the Haynes manual and the Mitchell on Demand systen for my wiring diagrams.

Check out my web site. I used James Duff mounts.

Dead Link Removed

The wiring part of the conversion was succesfull!! Thanks for all the Help. It was not as bad as I thought it would be! Feel Free to ask questions...

and check out the results of my conversion which I have posted in a new thread....on the conversion page