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

Alternator wiring help!

  • Thread starter Thread starter ty50650
  • Start date Start date Apr 28, 2025
T

ty50650

Member
Jan 29, 2024
6
5
13
Bay Area
Apr 28, 2025
#1
  • Apr 28, 2025
  • #1
Hello, I have a 1990 Mustang 5.0 that had a bad alternator. I originally bought a replacement from oreillys which had the rectifier plug connected to the new one with 3 wires coming out to crimp connect to the harness. I had cut off the alternator connector from my mustang (shouldn’t have) and was going to crimp together but decided to order an oem replacement from LMR instead that would connect directly to the replacement alternator. Now I have a new plug that I am trying to connect and am wondering how to tell which orange and black wires connect to which. I should have labeled them but did not. I’ve attached pictures for better clarification.

If anyone could let me know how I could determine which wire goes to which, it would be greatly appreciated. Thanks for your help!
 

Attachments

  • IMG_0729.webp
    294.5 KB · Views: 99
  • IMG_0728.webp
    106.6 KB · Views: 87

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,353
21,555
234
Box behind Walmart
Apr 28, 2025
#2
  • Apr 28, 2025
  • #2
It doesn't matter, they both go to the same place.

I would solder those connections vs. using barrel connectors.

You [could] also, cap those wires and tuck them out of the way. Run a a new [fused] 4 gauge wire from the alternator to the [Hot] post of the start solenoid.

Refer to this post for a bit more clarification: https://stangnet.com/mustang-forums/threads/3g-alternator-install-a-how-to.646825/#post-6673702
 
Reactions: Mcmahst
You must log in or register to reply here.

Similar threads

S
Resolved 83 alternator wiring harness
  • sparten5000
  • Aug 2, 2026
  • Fox 5.0 Mustang Tech
Replies
2
Views
150
Fox 5.0 Mustang Tech Aug 23, 2026
limp
Resolved Wiring electric fan
  • cbac89
  • Aug 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
3
Views
159
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Aug 30, 2026
cbac89
A
Resolved Electrical Help Please
  • Alabama
  • Jan 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
331
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 22, 2026
AeroCoupe
Alternator not charging
  • SchwarzStock
  • Jul 6, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
2
Views
168
1965 - 1973 Classic Mustangs -General/Talk- Jul 19, 2026
SchwarzStock
M
Alternator
  • miser143
  • Aug 4, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
6
Views
237
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Aug 5, 2025
manicmechanic007
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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?