3G alternator needed?

[Ramcharger90]

Im told I need a 3G alternator for the fox system to work properly. I have the alternator from a 5.0 98 mercury mountaineer. So if that isn't the right one I have who makes a 3G alternator that will mount to the 5.0 explorer/mercury accessory brackets? Or can I even get one?

 

[RonD]

Whats a "fox system"?

And what year 5.0l engine?
V-belt or serpentine

1998 mountaineer would be a 4G alternator, but would work fine in place of 3G, most opinions are 3G lasted longer than 4G, wiring connection to vehicle was the same
1998 would be serpentine belt

Info here on Ford Alternator generations, i.e. 3G, 4G and 6G: https://alternatorparts.com/ford-type-3g-4g-6g-series-high-output-alternators.html

 

[Bird76Mojo]

@RonD a fox system is the Foxbody Mustang platform.

I'm running the standard alternator that came on my 92 Thunderbird 5.0 engine. Which would be the same as the 94-95 SN95 Mustang. I'm also running the Ron Francis Telorvek system that uses a Foxbody A9P ECU. Runs great.

I can't see you needing to switch alternators, but if you decide to dig deeper in to any conversion, then Ron Francis is a good company to check with. They make all sorts of alternator conversion harnesses with the correct factory wiring plugs on them. In many cases the color coding of the wires is even the same as Ford used in their systems.

Where did you get this info that you have to run a different alternator?

 

[Ramcharger90]

That mountaineer alternator only has the 2 wire plug and the bigger wire that attaches with a nut, It doesn't have that fire wire I think it was called. Ill be honest I am horrible with wiring and lil to no patience for it. So I would honestly just want to get a 3G alternator for that foxbody harness that will mount to the mountaineer/explorer alternator braket

 

[RonD]

2 wire "plug" just doesn't use the "White" loop wire, only uses Yellow and Green wires

So exactly the same 3 wires to the vehicle:
B+, bigger wire that goes on the stud with nut
Yellow, regulator monitor
Green, ON/OFF

You just need the 2 wire plug that matches 4G plug in, splice it to the Yellow and Green wires

There is no white(3rd) wire in the truck harness

 

[Ramcharger90]

It has the mustang harness in now not the ranger harness

 

[RonD]

Wouldn't matter same Yellow and Green voltage regulator wires in either harness

B+ wire, for stud, will have 12volts all the time, hooked to battery positive thru larger mega fuse or fusible links
Yellow wire will also have 12volts all the time, hooked to battery positive thru smaller fuse, 15-20amp

Yellow wire can actually be cut and wired to Stud terminal with B+ wire, as needed

Green wire will only have 12volts with key on, its the ON/OFF switch for alternator, also Battery Light wire
It is Key on power, startup voltage needed by alternator



Since 2G, 2nd generation, alternators with built in voltage regulator, the wiring has become fairly standard, 3 wires from alternator to vehicle.
2G and 3G had "3 wire plug in" for voltage regulator but only 2 of the wires run to vehicle, 3rd wire(white) just looped back to alternator
4G had the 3rd wire inside, so just a 2 wire connector

All have the larger B+ wire on a stud/nut, usually, for Output voltage