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

Electrical Charging issue

  • Thread starter Thread starter sigsterrr
  • Start date Start date May 25, 2020

sigsterrr

Active Member
Jan 12, 2019
120
75
38
Florida
May 25, 2020
#1
  • May 25, 2020
  • #1
I cannot seem to figure out why my 89 gt with a 3g upgrade isn’t charging. Let’s start by confirming it is wired correctly please.





12 voltage at terminal on alt.
12 volts peach/white
Green black
 

sigsterrr

Active Member
Jan 12, 2019
120
75
38
Florida
May 25, 2020
#2
  • May 25, 2020
  • #2
Also, alt light bulb is good in dash
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
8,859
214
In the garage
May 25, 2020
#3
  • May 25, 2020
  • #3
Do NOT reuse the stock 2G alternator power wires. The only wire from that plug to reuse is the the stator wire. Get off of Ebay or the Corral the 4 gauge wire kit with the 150 amp fuse and wire that directly to the back of the alternator plug and to the starter solenoid terminal .

Here is the install instructions

3G Alternator Install: A How To

Here is what Mr. Alternator (864)591-1066 has. A 130amp alternator complete with stator wire, short bolt, and with no exchange required. Mine came with the standard finish for $145.00 with shipping included. I received it in about four days. As you can see from the picture the new 3G is...
www.stangnet.com
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
28,014
10,638
213
polk county florida
May 25, 2020
#4
  • May 25, 2020
  • #4
I agree, those wires in the pic are junk.
 

sigsterrr

Active Member
Jan 12, 2019
120
75
38
Florida
May 25, 2020
#5
  • May 25, 2020
  • #5
I checked the green/red wire at the dash and it has 12v so I am just going to run a wire from the dash to the alt. That should solve the problem.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
28,014
10,638
213
polk county florida
May 25, 2020
#6
  • May 25, 2020
  • #6
Keep a fire extinguisher in the car.
 
Reactions: Monkeybutt2000

sigsterrr

Active Member
Jan 12, 2019
120
75
38
Florida
May 25, 2020
#7
  • May 25, 2020
  • #7
General karthief said:
Keep a fire extinguisher in the car.
Click to expand...

Why?
 
M

Monkeybutt2000

Mustang Master
Aug 11, 2019
1,387
851
133
Lafayette,IN
May 25, 2020
#8
  • May 25, 2020
  • #8
Are those wire nuts on the INSIDE of the alternator??
 

sigsterrr

Active Member
Jan 12, 2019
120
75
38
Florida
May 25, 2020
#9
  • May 25, 2020
  • #9
Monkeybutt2000 said:
Are those wire nuts on the INSIDE of the alternator??
Click to expand...

Nope. It’s a wire covers.
 
You must log in or register to reply here.

Similar threads

A
Resolved Electrical Help Please
  • Alabama
  • Jan 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
320
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
150
1965 - 1973 Classic Mustangs -General/Talk- Jul 19, 2026
SchwarzStock
B
Electrical No charge from 3g alternator
  • BigShowJoe
  • Nov 9, 2024
  • Fox 5.0 Mustang Tech
  • 2
Replies
20
Views
1K
Fox 5.0 Mustang Tech Nov 18, 2024
Mustang5L5
J
Wipers won't work at all
  • jpfox
  • May 8, 2025
  • Fox 5.0 Mustang Tech
Replies
10
Views
603
Fox 5.0 Mustang Tech May 16, 2025
nickyb
N
Smog system TAD//TAB solonoids wiring malfunction
  • noob need help
  • May 5, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
285
Fox 5.0 Mustang Tech May 30, 2025
Mustang5L5
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?