• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

How many wires are comming out of the alternator harness?

  • Thread starter Thread starter mat82284
  • Start date Start date Aug 16, 2008
M

mat82284

Member
Jul 31, 2003
889
1
16
Aug 16, 2008
#1
  • Aug 16, 2008
  • #1
I recently installed a supercharger and never checked my voltage before but i figured my alternator was on it way out so i took it to kragen they tested it and said it was bad. I bought a new 200amp alternator and installed it today, well it outputs the same voltage only 13.5 at idle and when everything is on 13.2-13.5 fluctuates. Also it wont go above 13.8 I have yet to see a 14 at all. This alternator did have a bigger pulley on it, not sure if that matters. Also when i rev to 2.5k the volts stays the same 13.5 Is this normal? How many wires are in the harness? I noticed 3 connection spots bu i only have to wires in the harness there located on the outside of the harness. I also installed a new 2g wire from the alternator to the battery. Could my car be causing the low voltage or did i get a bad alternator because i thought 14+ volts is what your supposed to see.
 
M

mat82284

Member
Jul 31, 2003
889
1
16
Aug 16, 2008
#2
  • Aug 16, 2008
  • #2
Can wiring be the reason for low volts or did i somehow get another bad alt?
 

COramprat

...I can take it. I think.
20+ Year Stangneter
Mar 2, 2003
8,474
1,463
223
Sea of Tranquility
Aug 16, 2008
#3
  • Aug 16, 2008
  • #3
Where are you measuring the voltage? The voltage regulator does what it says...regulates the voltage so that it doesn't fluctuate and damage the system. If you measure at the battery the voltage is at 12 volts when the engine is off. Once it is running it will be between 14-15 volts. The alternator is probably OK but the voltage regulator could be acting up...especially the ones made overseas. I had one crap out and melt the wiring harness for the alt. The additional sound system will draw down you amperage but the voltage should be good.
 
M

mat82284

Member
Jul 31, 2003
889
1
16
Aug 16, 2008
#4
  • Aug 16, 2008
  • #4
COramprat said:
Where are you measuring the voltage? The voltage regulator does what it says...regulates the voltage so that it doesn't fluctuate and damage the system. If you measure at the battery the voltage is at 12 volts when the engine is off. Once it is running it will be between 14-15 volts. The alternator is probably OK but the voltage regulator could be acting up...especially the ones made overseas. I had one crap out and melt the wiring harness for the alt. The additional sound system will draw down you amperage but the voltage should be good.
Click to expand...

Im checking the voltage at the alternator and the batttery. yesterday i seen 13.5v at the battery when the car was warm and 13.9 when it was cold. i seen 14.0 at the alternator and 13.6 at the alternator when warm. I was hoping i didnt get a bad alternator as i dont want to ship it out, but is there any possibility that something is wrong with my wiring? or is this all controlled by the voltage regulator?
 
You must log in or register to reply here.

Similar threads

Electrical Ron Francis Headlight / Alternator Harness
  • dan50
  • Apr 30, 2026
  • Fox 5.0 Mustang Tech
Replies
0
Views
230
Fox 5.0 Mustang Tech Apr 30, 2026
dan50
P
Electrical 2001 GT Overcharging
  • PseudoGT
  • Dec 3, 2025
  • SN95 4.6L Mustang Tech
Replies
1
Views
265
SN95 4.6L Mustang Tech Dec 13, 2025
Noobz347
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
Big Posi and Neg wire from Starter to Battery and Alt wires..........
  • from6to8
  • Feb 9, 2026
  • 1994 - 1995 Specific Tech
Replies
1
Views
224
1994 - 1995 Specific Tech Feb 9, 2026
AeroCoupe
F
Electrical From scratch: alternator wiring
  • fox racer v2
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
0
Views
584
Fox 5.0 Mustang Tech Jun 23, 2025
fox racer v2
F
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L 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?