• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Fuel Pump Wire Hunt Down

  • Thread starter Thread starter KaLiKo Street
  • Start date Start date Mar 15, 2012

KaLiKo Street

Member
Feb 2, 2012
73
0
6
Mar 15, 2012
#1
  • Mar 15, 2012
  • #1
Alright in the middle of my swap today (92 mustang 2.3 to 90 mark vii 5.0) I could not figure out where in the hell my fuel pump relay switch was...On my car the wires go like this, pink/black wire comes out of the fuel pump into the trunk and into the inertia switch, the pink/black wire then comes out of the the inertia switch as a green/yellow wire and travels up the drive side under the carpet in to a little black plug with some other wires on it. It then stays a green/yellow wire out the other side of the connector and runs behind the dash, travels down to a little green connector with some wires on it, comes out of the connector as a "(idk what color wire?)" and goes straight into the eec pin #22. Not once does it go into a relay, I believe that my relay is in the big black box on the passenger side strut tower with some other relays, looks like a mini eec kind of...But I down see where it would go from the green connector to that box in the engine bay. Maybe I missed it somehow it was dark outside...but I am positive that the green/yellow wire comes from the inertia switch up to the underside of the passenger side dash without ever going through a relay (not under either seat) I run it out to the battery and touched it with the + and the fuel pump cut on but im a little confused about the relay situation...wheres jrichker at???

I have Ford/Lincoln EVTMs and Factory Ford Manuals but there not really helping in this case...they list the wire as being black/pink all the way up to a relay under the drivers seat...
 

jcgafford

10 Year Member
Jan 7, 2012
1,114
95
104
Adrian, MI
Mar 15, 2012
#2
  • Mar 15, 2012
  • #2
playing with the same stuff, kinda. if all the 92's are the same with relay location then yours should be like my 5.0. two relays on passengercside strut tower, under the maf setup. one is the fuel relay and the other is a/c wot relay. if it is not there for some weird reason look under the drivers seat. it should be on the strut tower, clipped on right next to the a/c relay or hanging there close by. they share the end of the same wiring harness on mine
 

KaLiKo Street

Member
Feb 2, 2012
73
0
6
Mar 16, 2012
#3
  • Mar 16, 2012
  • #3
I didnt have any relays in the engine bay at all.

I believe that your talking about these relays in the pic below jcgafford?


But mine looks like this, no relays there just a black box

The black box "IRCM" i believe

Ima open this thing up tomorrow and see what makes it tick inside...
 

jcgafford

10 Year Member
Jan 7, 2012
1,114
95
104
Adrian, MI
Mar 16, 2012
#4
  • Mar 16, 2012
  • #4
Hey Bud I Just Wanted To Let You Know I Have A 1993 Mustang 2.3 Auto That I Converted To A 5.0 Manual And The Fuel Pump Relay Is Under The Hood On The 8 Plug 4cyl. It Is Located On The Passergerside Of The Motor. Its Not A Common Relay It Is A Black Box On A Bracket With A Bunch Of Wires Running To It. I Ran Into This Problem When I Swaped The V8 I Had To Wire A Fuel Pump Relay Directly Into The Computer. Oh And Ps If U Have The Problem Agin Get A Test Light That Will Suplly A 12volt Current And Power The Fuel Pump From The Trunk Under The Spare. If It Runs U Know The Problem Is Else Where. Hope This Helps
 

jcgafford

10 Year Member
Jan 7, 2012
1,114
95
104
Adrian, MI
Mar 16, 2012
#5
  • Mar 16, 2012
  • #5
post i grabbed quick. listed above. looks like you found it. apparently ford combined stuff on the 2.3
 

jcgafford

10 Year Member
Jan 7, 2012
1,114
95
104
Adrian, MI
Mar 16, 2012
#6
  • Mar 16, 2012
  • #6
http://www.stangnet.com/mustang-forums/threads/ircm-relay-box.515313/
 

KaLiKo Street

Member
Feb 2, 2012
73
0
6
Mar 16, 2012
#7
  • Mar 16, 2012
  • #7
That link you just posted states that the EEC power relay and Fuel pump relay are in the box...What I have done is removed the entire 2.3 wiring harness from the engine bay and spliced a Lincoln Mark VII 5.0 harness in its place and into the rest of my 2.3 harness in the car. I already have a EEC power relay that was in the 5.0 harness and it work with EEC like it should. I wonder if I can just use one of my other spare relays and splice the green/yellow wire into it and what ever other wires and make it work that way...because I cant use the IRCM with the 5.0 so I have to come up with something...

Thanks for your help though jcgaffod
 

jcgafford

10 Year Member
Jan 7, 2012
1,114
95
104
Adrian, MI
Mar 16, 2012
#8
  • Mar 16, 2012
  • #8
check the trunk, asked a buddy that wrenched on one. he guarantees its in there. under the carpet i would guess for the 90 vii relay location. that sounds like the problem, it wasn't on the harness you swapped. instead it was on the leftovers
 
You must log in or register to reply here.

Similar threads

W
Engine My engine dies after running 10 to 15 minutes under high heat.
  • Wylieone
  • Jun 21, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
86
Fox 5.0 Mustang Tech Monday at 8:13 AM
Mustang5L5
Electrical 91 hatch wiring help needed
  • FastDriver
  • Apr 7, 2026
  • Fox 5.0 Mustang Tech
Replies
2
Views
137
Fox 5.0 Mustang Tech Apr 8, 2026
FastDriver
S
1990 foxbody 5.0 fuel system.
  • staceyj
  • Nov 28, 2025
  • Fox 5.0 Mustang Tech
Replies
8
Views
359
Fox 5.0 Mustang Tech Nov 28, 2025
Mustang5L5
U
No fuel pump relay in harness
  • Uli661
  • May 18, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
4
Views
118
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 1, 2026
Uli661
U
B
Electrical Fuse 8, Light Green / Black Wire
  • bleedinggreen
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
7
Views
397
Fox 5.0 Mustang Tech Jun 26, 2025
bleedinggreen
B
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?