After doing a ton of research a while back as my OEM 21,000 mile alternator started going down the tubes, I figured there were some things about our alternators worth sharing. Much of this information is taken from the Electrical page of my own site, but it was just as easy to re-post and link it here.
I'll also skip most of the basics on how alternators work (converting AC power to DC via the rectifier), but there is plenty out there on the internet if you want more information. One document that I found that is fairly informative, entitled Understanding the Alternator, is a nice read though, especially since it explains the internal functions in detail and also differentiates between the stator windings. Definitely a good read! Otherwise, this picture is a good start:
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In a nutshell, the unique 6G, or Sixth Generation, OEM Terminator alternator is rated at 105A (sometimes listed as 110A). IT'S NOT 130A. Even worse, it's basically just the V-6 alternator with an 8-rib pulley and a different battery cable post on the back...
Since I ultimately had a local rebuilder upgrade my original to 160A, he not only showed me a bunch of information in his computer system where his parts come from (again, not 130A stuff), he also put two other Terminator alternators on his bench to confirm their output. One was another OEM take-off that I acquired afterwards, with 20,000 miles, and the other is a brand new Ford "reman". The first put out just over 110A and the "new" one, getting spun ridiculously high, was barely able to hit 120A, sometimes a hair over (and they both got nice and warm). Not being an expert on the subject, I believe what the shop owner stated about how a true 130A alternator would have been able to hit levels higher than 130. I guess they are rated conservatively. What's even more unusual, is the spare has a label on the case with "135A" printed on it, but it definitely did not deliver:
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Taking a step back, Ford is the only place that listed, and still lists, these alternators at 130A - as did FRPP not too long ago - but I think that is information that just slipped through the cracks back in 2002 and gets taken as gospel and repeated. The Order Guide does show a "Heavy duty" alternator, but I think that was what Ford intended, rather than what they delivered. It is not listed as "New For This Model Year", rather as the same information that most likely carried over from the '01 Cobra.
Apparently, there are plenty of guys that are aware of the lower output rating, but some still insist otherwise (I initially though they were 130A as well, until the research set in). The alternator we got is considered a "small case" unit, that definitely is not of the "high output" variety. The way to tell one from another easily:
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With that in mind, here is a pic from the brochures and the Press Kit that I'm guessing is a pre-production engine with a "large case" 4G alternator on a mount that is definitely different:
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Compare this to a production engine with the small case 6G alternator which doesn't jut out as much (a good thing since there is only about an inch between the case and the frame rail):
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As it stands, I had to dig more after searching through a bunch of vendor sites (RockAuto, CarQuest, Advance Auto, AutoZone, etc.) and coming up with nothing but 105A alternators. Since having mine rebuilt, and then having the shop show me how really easy it is, I decided to start looking around at vendors that sell parts for the DIY types that would tackle this on their own. One place with some great information (including many Ford engineering numbers to cross reference) is Alternator & Starter Parts Wholesale. Here is a screen shot from a search under "2003 Mustang" on their site:
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Once you are there and click the line for the Terminator (or any other), it opens up a list of all the components with many of the Ford engineering numbers. Just for the heck of it, I took those pages that I also found in another catalog and put them in a PDF document with everything Terminator-specific circled: all listing 110A - and mostly shared with the '01-'04 V-6 alternator. Here is also a GENERIC picture of those parts that can be pulled from the above site:
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The screen shot up above also references a "Lester 8304" alternator, and if you also want to search under the engineering number info on the rear bearing cap ("FN 2R3V-BA") a bunch more listings also come up showing only 105A replacements. Here are a few more examples:
http://catalog.remyinc.com/Product/Details/23750?
http://www.dbelectrical.com/p-7254-new-alternator-46-46l-ford-mustang-2003-2004-03-04.aspx
http://www.totalpowerparts.com/p-1029-new-alternator-for-46-46l-ford-mustang-03-04-2003-2004.aspx
Something else interesting when mine was undergoing its transformation: mine worked perfectly with a 2-1/8" pulley to replace the original 2-1/2". Forum lore suggests that the OEM alternators are "over spun", but the owner of the shop assured me that he's never seen high RPM's kill them (well, unless the bearings are shot), rather it is the heat that wipes out the diodes in conjunction with plenty of abuse. For now, the small pulley on mine is doing the trick, and since I have the stock crank pulley and don't intend to race, I figure I'll be fine by not regularly spinning the hell out of it. Here's the "new" one:
![]()
Anyway, I know that plenty of guys dive in and upgrade to something from Mechman, Nations, etc., but I also wanted to point out how easy it is to not only acquire parts for these, but to rebuild one yourself (again, with NEW parts). They can also be had from local chain stores, and in a pinch, the V-6 alternator is easier to acquire - just don't forget to change the pulley and the post. Thanks to YouTube, another vendor even has a video that shows the re-build process and how straightforward it is if you take that route. Since there are no more new alternators available directly from Ford, this isn't a bad way to go:
I hope this information proves to be useful.
I'll also skip most of the basics on how alternators work (converting AC power to DC via the rectifier), but there is plenty out there on the internet if you want more information. One document that I found that is fairly informative, entitled Understanding the Alternator, is a nice read though, especially since it explains the internal functions in detail and also differentiates between the stator windings. Definitely a good read! Otherwise, this picture is a good start:
In a nutshell, the unique 6G, or Sixth Generation, OEM Terminator alternator is rated at 105A (sometimes listed as 110A). IT'S NOT 130A. Even worse, it's basically just the V-6 alternator with an 8-rib pulley and a different battery cable post on the back...
Since I ultimately had a local rebuilder upgrade my original to 160A, he not only showed me a bunch of information in his computer system where his parts come from (again, not 130A stuff), he also put two other Terminator alternators on his bench to confirm their output. One was another OEM take-off that I acquired afterwards, with 20,000 miles, and the other is a brand new Ford "reman". The first put out just over 110A and the "new" one, getting spun ridiculously high, was barely able to hit 120A, sometimes a hair over (and they both got nice and warm). Not being an expert on the subject, I believe what the shop owner stated about how a true 130A alternator would have been able to hit levels higher than 130. I guess they are rated conservatively. What's even more unusual, is the spare has a label on the case with "135A" printed on it, but it definitely did not deliver:
Taking a step back, Ford is the only place that listed, and still lists, these alternators at 130A - as did FRPP not too long ago - but I think that is information that just slipped through the cracks back in 2002 and gets taken as gospel and repeated. The Order Guide does show a "Heavy duty" alternator, but I think that was what Ford intended, rather than what they delivered. It is not listed as "New For This Model Year", rather as the same information that most likely carried over from the '01 Cobra.
Apparently, there are plenty of guys that are aware of the lower output rating, but some still insist otherwise (I initially though they were 130A as well, until the research set in). The alternator we got is considered a "small case" unit, that definitely is not of the "high output" variety. The way to tell one from another easily:
With that in mind, here is a pic from the brochures and the Press Kit that I'm guessing is a pre-production engine with a "large case" 4G alternator on a mount that is definitely different:
Compare this to a production engine with the small case 6G alternator which doesn't jut out as much (a good thing since there is only about an inch between the case and the frame rail):
As it stands, I had to dig more after searching through a bunch of vendor sites (RockAuto, CarQuest, Advance Auto, AutoZone, etc.) and coming up with nothing but 105A alternators. Since having mine rebuilt, and then having the shop show me how really easy it is, I decided to start looking around at vendors that sell parts for the DIY types that would tackle this on their own. One place with some great information (including many Ford engineering numbers to cross reference) is Alternator & Starter Parts Wholesale. Here is a screen shot from a search under "2003 Mustang" on their site:
Once you are there and click the line for the Terminator (or any other), it opens up a list of all the components with many of the Ford engineering numbers. Just for the heck of it, I took those pages that I also found in another catalog and put them in a PDF document with everything Terminator-specific circled: all listing 110A - and mostly shared with the '01-'04 V-6 alternator. Here is also a GENERIC picture of those parts that can be pulled from the above site:
The screen shot up above also references a "Lester 8304" alternator, and if you also want to search under the engineering number info on the rear bearing cap ("FN 2R3V-BA") a bunch more listings also come up showing only 105A replacements. Here are a few more examples:
http://catalog.remyinc.com/Product/Details/23750?
http://www.dbelectrical.com/p-7254-new-alternator-46-46l-ford-mustang-2003-2004-03-04.aspx
http://www.totalpowerparts.com/p-1029-new-alternator-for-46-46l-ford-mustang-03-04-2003-2004.aspx
Something else interesting when mine was undergoing its transformation: mine worked perfectly with a 2-1/8" pulley to replace the original 2-1/2". Forum lore suggests that the OEM alternators are "over spun", but the owner of the shop assured me that he's never seen high RPM's kill them (well, unless the bearings are shot), rather it is the heat that wipes out the diodes in conjunction with plenty of abuse. For now, the small pulley on mine is doing the trick, and since I have the stock crank pulley and don't intend to race, I figure I'll be fine by not regularly spinning the hell out of it. Here's the "new" one:
Anyway, I know that plenty of guys dive in and upgrade to something from Mechman, Nations, etc., but I also wanted to point out how easy it is to not only acquire parts for these, but to rebuild one yourself (again, with NEW parts). They can also be had from local chain stores, and in a pinch, the V-6 alternator is easier to acquire - just don't forget to change the pulley and the post. Thanks to YouTube, another vendor even has a video that shows the re-build process and how straightforward it is if you take that route. Since there are no more new alternators available directly from Ford, this isn't a bad way to go:
I hope this information proves to be useful.
.
