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

Grounding question

  • Thread starter Thread starter jstang209
  • Start date Start date Mar 14, 2009
J

jstang209

20+ Year Stangneter
Jun 3, 2004
640
2
18
Stockton 209
Mar 14, 2009
#1
  • Mar 14, 2009
  • #1
I did a 3g alternator upgrade now im going to add a 4guage ground wire(block to chassis). Does it need to go in another spot else or can I bolt it to the same spot my neg batt cable goes to?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Mar 14, 2009
#2
  • Mar 14, 2009
  • #2
The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects.

The 3G has a 130 amp capacity, so you wire the power side
with 4 gauge wire. It stands to reason that the ground side
handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & extra 3G
alternator ground wire as described above in paragraph 2. A screwdriver
points to the bolt that is the common ground point.
The battery common ground is a 10 gauge pigtail with the computer ground
attached to it.

Picture courtesy timewarped1972
 
You must log in or register to reply here.

Similar threads

D
Negative Grounds for 2008 4.0L
  • deadbeat
  • May 13, 2026
  • 2005 - 2014 Specific V6 Tech
Replies
0
Views
86
2005 - 2014 Specific V6 Tech May 13, 2026
deadbeat
D
A
Resolved Electrical Help Please
  • Alabama
  • Jan 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
297
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 22, 2026
AeroCoupe
W
Electrical 91 GT Alternator Replacement Question
  • willrh111
  • Oct 22, 2025
  • Fox 5.0 Mustang Tech
Replies
6
Views
377
Fox 5.0 Mustang Tech Oct 23, 2025
nickyb
F
Electrical From scratch: alternator wiring
  • fox racer v2
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
0
Views
585
Fox 5.0 Mustang Tech Jun 23, 2025
fox racer v2
F
Big Posi and Neg wire from Starter to Battery and Alt wires..........
  • from6to8
  • Feb 9, 2026
  • 1994 - 1995 Specific Tech
Replies
1
Views
225
1994 - 1995 Specific Tech Feb 9, 2026
AeroCoupe
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?