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302 alternator help is it 1g or 3g?

  • Thread starter Thread starter Miastang
  • Start date Start date Sep 20, 2020
M

Miastang

Member
Jul 4, 2020
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Uk
Sep 20, 2020
#1
  • Sep 20, 2020
  • #1
Hi everyone, I bought a car with 1990 302, the car has a fair few mods from headers to transmission, I’m changing the alternator but there is not a single identification number on it?? Can someone tell me if this is a 1 or 3g alternator please, all it has is motorcraft brand name and number 2 on it!
As it’s quite modified it may be likely they upgraded alternator too and understand there is a some wiring mods when upgrading to 3G so didn’t want to get the wrong one.

many thanks in advance
 

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96pushrod

I think they're a little easier to get off
5 Year Member
May 15, 2018
1,530
871
133
Savannah
Sep 20, 2020
#2
  • Sep 20, 2020
  • #2
Looks to be a 3g.
 
M

Miastang

Member
Jul 4, 2020
6
1
13
Uk
Sep 20, 2020
#3
  • Sep 20, 2020
  • #3
96pushrod said:
Looks to be a 3g.
Click to expand...

how would you tell the difference normally?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,249
17,934
224
Massachusetts
Sep 20, 2020
#4
  • Sep 20, 2020
  • #4
3g or 6G. Hard to judge its size by the pics

Appearance mostly. The 6g is a small case version of the 3g with better cooling, but I believe they are 110A. Came on 01-04 v6 Mustangs

this list is incomplete

How to Identify Your Ford 3G, 4G & 6G Series Alternator

How to identify key differences in Ford 3G, 4G and 6G Series alternators. Large Case High Output upgrade paths from your stock small case alternator.
alternatorparts.com

I believe the 86-93 mustang alt us considered a 2G alt
 

Blown88GT

Founding Member
Nov 13, 1999
2,283
524
164
Palm Beach Gardens, FL
Sep 20, 2020
#5
  • Sep 20, 2020
  • #5
Miastang said:
how would you tell the difference normally?
Click to expand...
2G has external fan
3G has internal fan.
 

CtCarl

Active Member
Apr 27, 2002
72
18
28
Southern Connecticut
Sep 20, 2020
#6
  • Sep 20, 2020
  • #6
FWIW, telling the 3G from the 6G when it's installed is pretty easy. If there's a stator wire, it's a 3G. If the alternator bracket is notched for clearance, it's a 3G.
 
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