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

Check Engine Light Help

  • Thread starter Thread starter SFC_R0CK
  • Start date Start date Oct 31, 2008
Prev
  • 1
  • 2
  • 3
  • 4
  • 5
Next
First Prev 3 of 5 Next Last

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Nov 30, 2008
#41
  • Nov 30, 2008
  • #41
Pin 30 LB/Y is 4 mt Pin 30 W/PK 4 auto.
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Nov 30, 2008
#42
  • Nov 30, 2008
  • #42
According to wire diagram I got from Autozone website pin 30 is the same color coming out of the 60 pin connector for both mt and at transmissions. I have the correct wire harness for an at installed as it has the white/pink wire and came with the transmission. I will check the voltage tomorrow and post results.

Thanks again for the time and help.
 

Attachments

  • 1989-1990_Body_Wiring.webp
    29.8 KB · Views: 130
  • 1989-1990_Engine_Wiring.webp
    42.2 KB · Views: 123

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Nov 30, 2008
#43
  • Nov 30, 2008
  • #43
My guess on cruse. you need a jumper 4 clutch pedal switch
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Nov 30, 2008
#44
  • Nov 30, 2008
  • #44
I dont have a clutch, its an AOD.

Thanks
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Nov 30, 2008
#45
  • Nov 30, 2008
  • #45
The car before swap mt or auto? Now would be 5.0 Ho with auto. I am in fords book not autozone .you have a mt harness .light blue with yellow stripe sounds like purple with yellow.white and pink is auto. As to pin 60 and 40 are power grounds and are black with light green. When you look on internet on codes it shows o/r/c what it does not tell you is what engine you have fords book shows 25 different engine combos. Reading this is how i got my findings from the codes you gave me. So are you sure still about pin 30?
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Nov 30, 2008
#46
  • Nov 30, 2008
  • #46
The car was an auto before the swap, I will double check the color of pin 30 tomorrow afternoon. All the research I did before I got this harness said that the computer harness did not matter if it was from a mt or at as long it was for the year was same. The harness that plugs into the neutral switch on the transmission and into the trans tunnel has the white/pink wires.

Thanks for the help.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Nov 30, 2008
#47
  • Nov 30, 2008
  • #47
Ok i think im maxed out on this .this is all i got pin 30 lb/y is circuit 199. W/PK is circuit 33 .i c a stick has a back up lite switch auto has nss.hisson your turn im listening
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Dec 1, 2008
#48
  • Dec 1, 2008
  • #48
Ok just checked pin 30 out of the computer harness and it looks like it is purple with a yellow stripe.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 2, 2008
#49
  • Dec 2, 2008
  • #49
I dont know if just 1 wire would screw you but why 2 different harnesses with circuit being different hope it is.ive had a blast with this thanks.ask hisson about any tricks or just change harness
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Dec 2, 2008
#50
  • Dec 2, 2008
  • #50
hotcobra03 said:
.......ask hisson about any tricks or just change harness
Click to expand...

I've been kinda following along and I think you did very well.

If it hasn't been checked (HC03 noted what to do in previous posts), finding the value of Pin 30 is the next step. That will suggest if the wiring or switch is likely to be the issue.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 2, 2008
#51
  • Dec 2, 2008
  • #51
Can he still use this harmess?my 03 manual breaks down to the spot welds on your car. My older is a paper book and i got those from ford and were like 200 per book im missing 2 of them .hission can you tell us where the two circuits run to ?back up switch and nss is my guess but hate to guess
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 2, 2008
#52
  • Dec 2, 2008
  • #52
Thanks hission.as you might have read after 30yrs of wrenching ive becomed a viberation specialist.our shop(father/son) was were you went after everyone else has tried even dealer. Time to expand to code scanner specialist.anyway Can he still use this harmess?my 03 manual breaks down to the spot welds on your car. My older is a paper book and i got those from ford and were like 200 per book im missing 2 of them .hission can you tell us where the two circuits run to ?back up switch and nss is my guess but hate to guess.
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Dec 2, 2008
#53
  • Dec 2, 2008
  • #53
Thanks hotcobra03 and HISSIN50 for the time and help. I was not able to check the voltage but will do my best to test it tomorrow. Just to make sure I read correctly I will be looking for :

hotcobra03 you said to check

Pin 30 to ground is less than 1 volt if not then the nss is bad correct?

Pin 30 to ground is more than 1 volt if not then the ac clutch is bad correct? But I do not have ac installed so it should less than 1 volt unless there is another problem right?

do I check this at pin 30 on the computer plug harness or do I check this at the plug on the nss on the transmission?

Thanks again for all the help.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 2, 2008
#54
  • Dec 2, 2008
  • #54
U need to change harness.code 67 mt your neutral drive switch pin test done 30 to 46. With auto neutral drive input pin 30 to chassis.pin 30 goes to eca and vss cruise and horn are tied .testing now is a waste of time
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Dec 3, 2008
#55
  • Dec 3, 2008
  • #55
Ok I checked the voltage at PIN 30 on the computer harness to ground and got -4.74
and then I unplugged the harness at the transmission tunnel and checked the voltage on one of the 4 pins there and got -11.83 to the chasis.

Thanks for the help guys.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Dec 3, 2008
#56
  • Dec 3, 2008
  • #56
I would check In/out voltage at the switch. It sounds like the switch might be bad.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 3, 2008
#57
  • Dec 3, 2008
  • #57
Pin 30 lb/yellow wire is what you have you need the other harness for auto with pin 30 white/pink stripe.im guessing here harness from pass side kick panel pcm 60 pin plug as harness wraps through engine bay under master cyl and inside car to eca driver side underdash.67 is your problem.lb/y to pin 46 with ac switch off ck ohms .less than 5 ? White and pink 30 to cha . Less than 1 v ?
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Dec 3, 2008
#58
  • Dec 3, 2008
  • #58
HISSIN50, this is probably going to sound like a really stupid question but how do I check the in/out voltage at the switch. Electrical has never been my strong point and I am learning this stuff as I troubleshoot this.

Thanks for the advice so far.
 
S

SFC_R0CK

Member
Oct 30, 2008
81
0
7
AL
Dec 3, 2008
#59
  • Dec 3, 2008
  • #59
hotcobra03, pin 30 to 46 at the 60 pin computer harness plug with the ac switch off was 2.1 ohms.

The white/pink pin on the connector under the car at the trans tunnel to chasis was -.009 v

Thanks for the patience.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 3, 2008
#60
  • Dec 3, 2008
  • #60
Question ?the 4 pin plug at trans how many wires and colors
 
Prev
  • 1
  • 2
  • 3
  • 4
  • 5
Next
First Prev 3 of 5 Next Last
You must log in or register to reply here.

Similar threads

A
Check Engine codes jumping around
  • azactor
  • Jan 9, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
161
1996 - 2004 SN95 Mustang -General/Talk- Jan 10, 2026
gkomo
F
Electrical From scratch: alternator wiring
  • fox racer v2
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
0
Views
527
Fox 5.0 Mustang Tech Jun 23, 2025
fox racer v2
F
A
Resolved Electrical Help Please
  • Alabama
  • Jan 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
241
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 22, 2026
AeroCoupe
T
2002 V6 3.8L Help Me
  • TheIncompetentMechanic
  • Apr 4, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • 2 3
Replies
50
Views
671
1996 - 2004 SN95 Mustang -General/Talk- May 12, 2026
TheIncompetentMechanic
T
S
Preparation for Holley Terminator X install – Foxbody 306 (electrical fan, alternator, MSD Ignition, etc)
  • So_Flo
  • Mar 1, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
22
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Mar 4, 2026
General karthief
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?