Mustang II One Wire Alternator Conversion?

IICrew

Mustang Master
Mar 29, 2020
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We are talking a 50's Thunderbird replica. He is upgrading from what was probably a 60 amp alternator to at least a 100 amp. It will never be worked hard in this application unless he has a lot of electrical goodies added on. Heat will not be an issue. This style alternator has a proven track record of 50 plus years. He has nothing to worry about.

You on the other hand. If your going through alternators like that you have one hell of a draw, :poo:ty luck or a wiring issue causing the alternator to fail. I have been working on cars since the early 80's and have never had any car need that many alternators. I spent a couple decades in dealerships and or service shops in various roles and have never had a car eat alternators like that. Most cars the past 25 years or so go their entire lives on the factory alternator. I have several 90's cars with 200k plus on original alternator here in my driveway. Two of which I bought with under 30k miles on them. I have a 2000ish impala I bought from the original owner with just over 300k now. Original engine, trans, and alternator. He only replaced brakes, tires and battery. Your car has an issue or you have horrible luck.
 
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mustystang

Claiming to be an Alpha Chassis
Aug 20, 2022
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We are talking a 50's Thunderbird replica. He is upgrading from what was probably a 60 amp alternator to at least a 100 amp. It will never be worked hard in this application unless he has a lot of electrical goodies added on. Heat will not be an issue. This style alternator has a proven track record of 50 plus years. He has nothing to worry about.

You on the other hand. If your going through alternators like that you have one hell of a draw, :poo:ty luck or a wiring issue causing the alternator to fail. I have been working on cars since the early 80's and have never had any car need that many alternators. I spent a couple decades in dealerships and or service shops in various roles and have never had a car eat alternators like that. Most cars the past 25 years or so go their entire lives on the factory alternator. I have several 90's cars with 200k plus on original alternator here in my driveway. Two of which I bought with under 30k miles on them. I have a 2000ish impala I bought from the original owner with just over 300k now. Original engine, trans, and alternator. He only replaced brakes, tires and battery. Your car has an issue or you have horrible luck.
Google this: "Mustang 2008 check charging system", or 2006, 2007. You will see hundreds of people posting about it. I have spent so much time reading everything there is about it. No one can find the problem. And even if someone claims to find the problem, they are usually back saying it hasn't actually fixed the problem. I have tried just about every solution possible. My current solution is charging the car every night now. I do have the shaker 500 sound system that came with the pony package, and I do crank up my music and listen to some heavy loud. But a long time ago I had a car with 2 12's in the back that was probably 100x louder than what I currently have with no alternator issues. So I don't think my music volume is the problem. I'm thinking it's a computer thing and the electrical engineer who worked on the designs overlooked something. If I don't drive the car every day it strains the alternator. And 200 amp alt won't fully fix the problem. I may just start putting a new battery in every 2 years to see if I can get a jump on the problem. Trust me I am frustrated. I am actually going to start learning how to start fixing my own alternators. I already have 2 burnt ones that I can fix up lol. Hopefully I can get them running before my new one fails. Or maybe the smart charger will take care of the issue for me. May look into a capactitor or something too.
 

mustystang

Claiming to be an Alpha Chassis
Aug 20, 2022
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Have you never looked under the hood of an American car built before 1995 or so? Virtually everything GM or Ford built ran an alternator that looked like that from the 1960s until then, and AMC and Chrysler even got on board in the 1970s.
I guess I forgot what year the car was. Anything past 2005 has so much computer crap drawing power now. 2005-2009 mustangs eat alternators, I'm not the only one. Especially if you have the pony package with the shaker 500 sound system.
 

MustangIIMatt

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Google this: "Mustang 2008 check charging system", or 2006, 2007. You will see hundreds of people posting about it. I have spent so much time reading everything there is about it. No one can find the problem. And even if someone claims to find the problem, they are usually back saying it hasn't actually fixed the problem. I have tried just about every solution possible. My current solution is charging the car every night now. I do have the shaker 500 sound system that came with the pony package, and I do crank up my music and listen to some heavy loud. But a long time ago I had a car with 2 12's in the back that was probably 100x louder than what I currently have with no alternator issues. So I don't think my music volume is the problem. I'm thinking it's a computer thing and the electrical engineer who worked on the designs overlooked something. If I don't drive the car every day it strains the alternator. And 200 amp alt won't fully fix the problem. I may just start putting a new battery in every 2 years to see if I can get a jump on the problem. Trust me I am frustrated. I am actually going to start learning how to start fixing my own alternators. I already have 2 burnt ones that I can fix up lol. Hopefully I can get them running before my new one fails. Or maybe the smart charger will take care of the issue for me. May look into a capactitor or something too.

I guess I forgot what year the car was. Anything past 2005 has so much computer crap drawing power now. 2005-2009 mustangs eat alternators, I'm not the only one. Especially if you have the pony package with the shaker 500 sound system.
I've had a 2009 and a 2010 (mechanically identical to the 2009, but different interior and some body revisions). Neither had a single alternator problem, and the '09 had the Shaker system. My best friend had an '05 for three years and we put one alternator on it.

I'm also a former Ford dealer tech (I work for GM now, worked for CarMax and BMW in between the two), and could count on one hand the number of alternators I've installed on S197 Mustangs.

If you're replacing alternators constantly, you're either installing low quality rebuilds or the problem is something else and the alternator failures are actually a symptom and not the root cause.
 

3djedi

Member
Aug 24, 2022
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The power to the car is supplied by a wire on the solenoid. I believe it will be a yellow wire with a fusible link. You should have a heavy gauge wire on the solenoid running to the main harness. It will be on the same terminal as your positive battery cable. I have a remote battery so I ran the 1 wire from the alternator to the solenoid. Installed a ground and called it a day.
Thank you for the great info. Looks like I can remove the alternator harness completely then without fear.
 

IICrew

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Mar 29, 2020
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I read some of the google results. Looks like Ford cut some corners again on your alternator. I was a Ford service advisor for several years. I went through their certified commercial advisor training. One thing that stuck out to me from that was they pay actuaries to scour warranty claims. If there is NOT enough failures they tell the vendor they are cutting a percentage of what ford will pay for that part. Then it's up to the vendor to cheapen the manufacturing of the part until they get the desired failure rate. The Ford suit that told us was proud of it. They had saved a lot of money. He had no idea he was bragging to service advisors who were disgusted by that. That made our job harder. I am sure other manufacturers do it but I have a lot of disdain for modern Fords.

My sister (escape), my son (fiesta), my daughter ( baby escape aka ecosport), and my son in law( focus st) bought brand new Fords between 2012 and 2016. All were a nightmare. All due to cost cutting. None of them will ever buy another Ford. None of the vehicles made it past 50,000 miles. I had owned and promoted Ford to my family. I cost them a lot of headaches. The only one I think was well built is my moms 2001 Escape. Over 20 years ago she bought it new and it now has about 55,000 miles. So it is not a good barometer.

Today there is Dodge, GM and Mustang II's in my stable. None are Ford products as Ford abandoned the II's way back when.
 

LILCBRA

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Ford abandoned the II's way back when.

Ford has abandoned a lot in the last however many years. When I had the chance to buy a new vehicle after my accident in 2015 - and even now when I toss the idea around - Ford has hardly been on my radar. They're destroying themselves.....
 

IICrew

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My sister bought a used 08 Tundra to replace her 2012 escape after multiple ac and electrical issues. She fought that car until the warranty was about to expire. My sons fiesta was rear ended at 3 years old. He had about 45k on it. The imitation steel rear bumper had already rusted away to the point the c shape was just flat. It folded like paper. The Acura sedan that hit him drove away. His car was totaled. The rear doors wouldn't open and the front doors were hard to open. He drives a Dodge Journey and after 5 years it's been trouble free. My daughters eco-whatever had the coolant issues. Was in the shop repeatedly. After picking it up from Ford for the 2nd engine in under 30k she drove straight from ford service dept to subaru. My son in law had the manual Focus st which was always throwing codes and missing. The fix was just dealing with it. He started having trans issues and dumped it for a honda suv. They don't have kids but he was so frustrated with the (sporty) Focus he now drives a honda suv and loves it. Turned him off sporty cars all together.

Maybe the above is why they stopped making sedans. Not the public didn't want sedans. It's that the public stopped buying Ford cars as they have turned to :poo:.
 

3djedi

Member
Aug 24, 2022
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Thank you everyone for the suggestions/help/tips. Greatly appreciated! Note the previous 10 gauge wire coming off of the alternator and trapped between the alternator and block. Didn't like it but thought I had to live with it. Didn't know anything about clocking an alternator until yesterday. Removed and clocked 180 degrees to clear the block and also changed 10 gauge (manufacturer instructions) to 6 gauge (per forum recommendations). Will work way better now!

alt_wiring.JPG alt_wiring2.JPG
 
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MustangIIMatt

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My sister bought a used 08 Tundra to replace her 2012 escape after multiple ac and electrical issues.

I replaced a 2014 F150 that I bought new with a 2008 4Runner after three years. Zero regrets, that Toyota just soldiers on day in and day out without any of the annoying issues the F150 brought to my daily commute.

I think we officially have the most hijacked thread in the II forum going on here... :rlaugh:
 
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3djedi

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I replaced a 2014 F150 that I bought new with a 2008 4Runner after three years. Zero regrets, that Toyota just soldiers on day in and day out without any of the annoying issues the F150 brought to my daily commute.

I think we officially have the most hijacked thread in the II forum going on here... :rlaugh:
Fine by me ...since I got the info I was looking for! Thank you again!
 

mustystang

Claiming to be an Alpha Chassis
Aug 20, 2022
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I've had a 2009 and a 2010 (mechanically identical to the 2009, but different interior and some body revisions). Neither had a single alternator problem, and the '09 had the Shaker system. My best friend had an '05 for three years and we put one alternator on it.

I'm also a former Ford dealer tech (I work for GM now, worked for CarMax and BMW in between the two), and could count on one hand the number of alternators I've installed on S197 Mustangs.

If you're replacing alternators constantly, you're either installing low quality rebuilds or the problem is something else and the alternator failures are actually a symptom and not the root cause.

At gas station today I struck up a convo with an old gentleman who had a 2004 Mustang GT. Without even saying anything to him he said "only issues I've had is with the alternator and battery" I started laughing and told him me too. He popped the hood for me and he had a quick disconnect switch to cut the draw when he doesn't drive it. He said a shop guy told him that if he doesn't drive it enough the battery will drain due to all the electrical demand. I've known this from experience though.

And if you worked for ford, you must know that no one takes their car to ford. The cars that are affected are just out of warranty when they start going bad. I've always used mom and pop shops, but after a few times in a row I thought maybe Ford would finally know something and be able to fix it, that's the only reason I went to ford and never again. They just swept the problem under the rug and sold me the whole under warranty speech, without specifying labor wouldn't be included when the alternator goes bad. They also completely disregarded my plea to put in a 2010 3g alternator and said it was out of spec. At least they gave me a complimentary rental before charging me freaking $900 for a basic alternator exchange. I was stuck at work with no options, I had already had the car towed there and they kept under shooting how much it would cost out the door. When it started going bad again I took it back to Ford, she said I would have to pay over $150 or so just to have them look at it, I drove off knowing I could put that towards a new alt and fix it myself since they continue to play their games.
 

mustystang

Claiming to be an Alpha Chassis
Aug 20, 2022
112
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I read some of the google results. Looks like Ford cut some corners again on your alternator. I was a Ford service advisor for several years. I went through their certified commercial advisor training. One thing that stuck out to me from that was they pay actuaries to scour warranty claims. If there is NOT enough failures they tell the vendor they are cutting a percentage of what ford will pay for that part. Then it's up to the vendor to cheapen the manufacturing of the part until they get the desired failure rate. The Ford suit that told us was proud of it. They had saved a lot of money. He had no idea he was bragging to service advisors who were disgusted by that. That made our job harder. I am sure other manufacturers do it but I have a lot of disdain for modern Fords.

My sister (escape), my son (fiesta), my daughter ( baby escape aka ecosport), and my son in law( focus st) bought brand new Fords between 2012 and 2016. All were a nightmare. All due to cost cutting. None of them will ever buy another Ford. None of the vehicles made it past 50,000 miles. I had owned and promoted Ford to my family. I cost them a lot of headaches. The only one I think was well built is my moms 2001 Escape. Over 20 years ago she bought it new and it now has about 55,000 miles. So it is not a good barometer.

Today there is Dodge, GM and Mustang II's in my stable. None are Ford products as Ford abandoned the II's way back when.
Thank you for the honest reply and actually taking the time to see what I'm talking about. It's issues like these that make me consider the camaro ss as well one day.
 

MustangIIMatt

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At gas station today I struck up a convo with an old gentleman who had a 2004 Mustang GT. Without even saying anything to him he said "only issues I've had is with the alternator and battery" I started laughing and told him me too. He popped the hood for me and he had a quick disconnect switch to cut the draw when he doesn't drive it. He said a shop guy told him that if he doesn't drive it enough the battery will drain due to all the electrical demand. I've known this from experience though.

And if you worked for ford, you must know that no one takes their car to ford. The cars that are affected are just out of warranty when they start going bad. I've always used mom and pop shops, but after a few times in a row I thought maybe Ford would finally know something and be able to fix it, that's the only reason I went to ford and never again. They just swept the problem under the rug and sold me the whole under warranty speech, without specifying labor wouldn't be included when the alternator goes bad. They also completely disregarded my plea to put in a 2010 3g alternator and said it was out of spec. At least they gave me a complimentary rental before charging me freaking $900 for a basic alternator exchange. I was stuck at work with no options, I had already had the car towed there and they kept under shooting how much it would cost out the door. When it started going bad again I took it back to Ford, she said I would have to pay over $150 or so just to have them look at it, I drove off knowing I could put that towards a new alt and fix it myself since they continue to play their games.
I worked for Ford when those cars were still new and under warranty. :rlaugh:

If Ford installed a Ford alternator, and it's what failed within two years of installation, it's absolutely under warranty. Find a different dealership, they can look up the previous repair in Oasis.
 

MustangIIMatt

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If you want to upgrade to the 2010 spec alternator, Remy has it under part number 12903, and AC Delco has it under 3343021. It's a Denso design that Denso themselves no longer remanufactures. Do me a favor and post a picture of your battery either here or in a thread in the S197 section.
 

mustystang

Claiming to be an Alpha Chassis
Aug 20, 2022
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I worked for Ford when those cars were still new and under warranty. :rlaugh:

If Ford installed a Ford alternator, and it's what failed within two years of installation, it's absolutely under warranty. Find a different dealership, they can look up the previous repair in Oasis.
Part is indeed under warranty, but the labor is not. I called and asked about it and also spoke to someone in person. They will still charge you labor. The labor charge is more than buying a new bigger alt myself and having another shop do it.

And I've upgraded the battery before too. It may have helped a little bit with the bigger alt, but it's a fine line because then there's more for the alt to charge when it drains. I have an AC Delco battery currently because that's what most recent shop carried. I think I had one long ago too. Ford put in a Motorcraft obviously. Currently just running stock size battery. And I'm not convinced 3g alt solves the problem entirely, especially for those who have serious parasitic draw. I've read numerous people still having the issues after trying the 3g alternator. Pretty sure it's a computer problem. Look up "CD Error" as well. CD player randomly tries to turn on when locked and no one is in the car. The discs spin and try to load but it just says CD Error then turns off after a minute. Happens throughout the night or whenever you open the car door. I have pulled fuses to the shaker 500 and to the radio/clock. I am not the only one with this issue. There are multiple posts of people claiming solutions on the internet and on youtube. I've been following the issue for years and have spent a lot of time reading about it. Just be glad it doesn't affect your car. And yes I've cleaned my terminslas and grounds. Multiple shops have checked my work, and also cleaned terminals themselves, and said everything looks fine it's not dirty terminals. I could go on and on for pages talking about this about other things I've tried. There is no solution, it's a schematics issue from the drawing board. Probably on purpose to ensure enough people buy the newer faster models. I'm sure there was a reason. I'm not mad I want that 420 hp mustang to be more affordable one day.
 

MustangIIMatt

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Part is indeed under warranty, but the labor is not. I called and asked about it and also spoke to someone in person. They will still charge you labor. The labor charge is more than buying a new bigger alt myself and having another shop do it.

And I've upgraded the battery before too. It may have helped a little bit with the bigger alt, but it's a fine line because then there's more for the alt to charge when it drains. I have an AC Delco battery currently because that's what most recent shop carried. I think I had one long ago too. Ford put in a Motorcraft obviously. Currently just running stock size battery. And I'm not convinced 3g alt solves the problem entirely, especially for those who have serious parasitic draw. I've read numerous people still having the issues after trying the 3g alternator. Pretty sure it's a computer problem. Look up "CD Error" as well. CD player randomly tries to turn on when locked and no one is in the car. The discs spin and try to load but it just says CD Error then turns off after a minute. Happens throughout the night or whenever you open the car door. I have pulled fuses to the shaker 500 and to the radio/clock. I am not the only one with this issue. There are multiple posts of people claiming solutions on the internet and on youtube. I've been following the issue for years and have spent a lot of time reading about it. Just be glad it doesn't affect your car. And yes I've cleaned my terminslas and grounds. Multiple shops have checked my work, and also cleaned terminals themselves, and said everything looks fine it's not dirty terminals. I could go on and on for pages talking about this about other things I've tried. There is no solution, it's a schematics issue from the drawing board. Probably on purpose to ensure enough people buy the newer faster models. I'm sure there was a reason. I'm not mad I want that 420 hp mustang to be more affordable one day.
Whoever you spoke to about the warranty is flat-out wrong. Ford themselves dictates warranty policy, not the dealership. If the part was installed by the dealership, labor is covered too. Hell, Ford will cover labor on a Motorcraft battery they didn't install if you have your receipt and it fails using their tester (that's the only thing they warranty that way). See the attached PDF.



If you have a parasitic draw, that's easy to diagnose. Eric The Car Guy has a how-to on YouTube.

Parasitic draws became a specialty of mine when I worked at BMW, where a door handle could wake up every module on the CAN-BUS repeatedly without registering a fault in any of them until the battery died, or the alternator could do it (yeah, those idiots put the alternator on the CAN), or the electric water pump, or the amplifier...

Hell, I really want to find one of these dealerships that doesn't honor warranty and doesn't make their techs back up a diagnosis, I could make a lot more money if I wasn't dealing with warranty pay rates or having to care if something wasn't fixed the first time.
 

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mustystang

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People have gone through all the steps chasing down a draw and still had problems. Maybe if you somehow scanned for 24 hours, I'm thinking it's something that's surging.

I'll have to dig though my records to see my warranty in writing, but even if you are correct, when it starts to die it's a miracle trying to get the problem to show up at the same time you bring it to the shop. The service would only be covered if they can prove the part is defective. I would end up paying Ford labor charge for an hour or so and be out money for no reason. There's no way they're going to not charge me if I bring it in and system checks out ok. The lady told me if nothing shows up then I would have to pay for the shop time. I have brought it to other shops multiple times and everyone thinks I'm crazy and they say it's showing that it's healthy and working properly. And yes I had them go through the full steps, not some basic battery check at autozone that tells you nothing. I showed them posts online of how to check and hopefully show something was wrong, they went above and beyond and still everything tested out within reason. It will intermittently be fine and then not fine, until you are completely broken down at the worst of times. So the light goes on and off before it starts to fail, and catching it when it says check charging system when you want it to is hard to do. One time I got the light, brought it immediately to the shop, and by the time they had it hooked up it had masked itself and they coudlnt find any issue. Shop literally thought I was nuts because I had gone back multiple times. I even had the guy get in my car and took him for a drive to try and recreate the problem and show him in person but unfortunately the light didn't come on. Went for a 15 to 20 minute ride and the guy had work to do couldn't spend all day trying to fix a customer's periodic alt problem, especilly when they tested it and it shows it's healthy and working within specs. I've been looking up this problem for over 5 years and have given up. $20 battery maintainer from here on out and hope that buys me some extra time. If you bored I recommend looking up the issue and reading everything from 20+ forums, come back in a couple months and let me know where you stand on the subject.
 
I did some of this w/my '70. From 60/90 amp G1 to the G3. Wanted to smooth the bay w/o the regulator (internal to the 130 amp). Thought I'd keep goin w/the mods & remove the starting solenoid from same inner fender (new wiring w/#2AWG, mega fuse, etc). I am re-thinking 2 things (got the look I wanted tho).
I). What's the more than 2X power increase gunna do to my 42 y/o wires (H4 headlights have new wiring/relays);
2). I'll put ina volt meter (on dash) as I imagine the amp meter will not work but all the extra wiring is off the ol solenoid just hanging. I'd like to put ina diode to save the dash wires, havea 'alternator light' but am not sure how.
Thnx ~
(dont think this is off topic. Let me know if it is & will run a separate thread)
 
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