Engine 3G alternator issues

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Blown88GT

Founding Member
Nov 13, 1999
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Simple visual alternator test:

External fan - 2G
Internal fan (not visible) - 3G or later

There are some 2G's out there that are "upgraded" 2G's with higher output.
I've heard them referred to as "1-wire alternators".
1-wire refers to one power wire for the alternator output.

All 3G's are 1-wire (plus one or 2 connectors for the voltage regulator)
 

CUAviator

Member
Jan 11, 2015
71
1
8
Simple visual alternator test:

External fan - 2G
Internal fan (not visible) - 3G or later

There are some 2G's out there that are "upgraded" 2G's with higher output.
I've heard them referred to as "1-wire alternators".
1-wire refers to one power wire for the alternator output.

All 3G's are 1-wire (plus one or 2 connectors for the voltage regulator)
That’s part of my issue - I don’t have anywhere to connect the “voltage regulator” connections.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
Well, that clears some things up. I think we need to get you over to the classic forums, our stuff (fox body) uses an internal regulator and the early models has an external regulator so the advice given here may not apply and we don't want any unintended fires. Give me a minute and I'll get a thread started for you over there.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
20,174
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polk county florida
I started a thread in the classic tech forums, here is a link:
Go there and post the pics of your alternator and the wiring and lets see what the members there think.
 

CUAviator

Member
Jan 11, 2015
71
1
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I started a thread in the classic tech forums, here is a link:
Go there and post the pics of your alternator and the wiring and lets see what the members there think.
Awesome, thanks. It’s just that since I’ve had this car, everyone has said that anything related to the engine (including my painless electrical) should be matched to the Fox engine. Is that not the case?
 

KRUISR

5 Year Member
Apr 16, 2015
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The charging system needs to be compatible with your chassis (rest of the car) except for whatever power requirement are needed for the fuel injection.

For example, if you have electric fans, the charging needs to be sufficient to support that.

If you wanted to do a 3G conversion that would give you plenty of juice and should be to be adapted to your car pretty easy. Personally I used an alternator and wiring pigtail from a 94-95 V6 mustang and modified/added to it to make it work in the Fox. They should be a 130amp alternator. I used a positive cable from a Windstar/Freestar as they are similar output alternators and use a larger gauge wire and the factory cable goes from passenger side of engine compartment to a driver front corner battery (much like the Fox body) so it is long enough.

Another vehicle that used a compatible 3G alt is the early 2000's Taurus. One difference is the voltage regulator is clocked differently on the back so it is pointing down (if I remember) which actually helps if you want to hide the wiring. A bit of a pain plugging it in though.
 

MustangIIMatt

Easy there, this ain't a dating site.
15 Year Member
Mar 7, 2002
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voltage regulator checked OK...UNTIL I turned on the AC, headlights, and stereo. At that point, the battery and alternator were reading ok but the voltage regulator FAILED (at both shops).

A) does anyone know why that happen?

Have this test re-run, but ONLY turn on the A/C, not the lights and radio.

If the alternator and/or regulator test bad with the A/C on and test good with it off, it's usually a bad A/C compressor clutch coil.
 

KRUISR

5 Year Member
Apr 16, 2015
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Me neither. But I’ve never seen it any other way either.
How is it supposed to be different? And does it matter?

Stock 90 Fox idle pulley location with smog pump and A/C...

20150404_184121.jpg

It shouldn't matter, so long as proper tension is maintained.