Alternator going out? "check charging system"

[fdjizm]

The electronic testers are junk. Only way to properly check is in car with a good machine. More important that voltage is amperage. Under load there is more amperage draw. If the draw is too large, it can cause the diode to go nuts! I would suggest replacing it now before you get stranded like you think.

That's what I was thinking, testing a lot of electronics at low load show nothing. I notice it's upon hard acceleration or slowing down from a quick 3rd gear pull on the highway.

My charge light use to come on like that. Set my Aeroforce to watch voltage. Voltage would be 14.x and then suddenly drop to 12 or less and light would come on. Sometimes it was 10 seconds, then it was 3 minutes. Voltage would go up to 14.x again and all would be fine. This went on for weeks. First 3 times the light came on it was every other week or two.

Finally bought a rebuilt from Advance Auto (stamped Motorcraft just like stock one) and it has been fine since- over a year. plus Advance has some great online coupons (big savings) to use and you can pick it up in the store.

Yea I will bet that is what is happening in that few seconds the alternator just drops off and picks back up... now i'm still conflicted on what alternator to buy!

edit: autozone is all duralast... any good?
Anybody have part number for the updated alternator? (heard there was a change after 05.)

 

[bcb06gt]

The price from Advance with their coupon is hard to beat.

 

[fdjizm]

Is this legit??

http://www.ebay.com/itm/Ford-Mustan...stang|Submodel:GT&hash=item589276eed9&vxp=mtr

 

[skwerl]

^ I'd be more inclined to get something from a large chain store with a lifetime warranty. What will you do if you buy the one off eBay and it goes bad in a year?

 

[fdjizm]

Smash my face into it.
I'm going to have to grab a vatozone duralast gold, lifetime warranty.
We shall see how that goes.

Bought this one..

http://www.autozone.com/autozone/pa...js59pZ9ci9i?itemIdentifier=120148_55002_4450_

going to pick it up tuesday.

 

[Department Of Boost]

It doesn't matter where/who makes/re-man's the 6G (stock) replacement alternators. The 6G design is highly flawed. They can last 5 years or 5 minutes. They have a basic design flaw. They come apart internally at higher RPM's (5000rpm+).

Ford switched to Denzo alternators in 2010 for this reason.

We have been using/testing some 4G 200A alternators with custom cases. They have been awsome!

 

[RetroGT2006]

My alternator did this at 32,700 miles and I had to have it replaced..

 

[fdjizm]

It doesn't matter where/who makes/re-man's the 6G (stock) replacement alternators. The 6G design is highly flawed. They can last 5 years or 5 minutes. They have a basic design flaw. They come apart internally at higher RPM's (5000rpm+).

Ford switched to Denzo alternators in 2010 for this reason.

We have been using/testing some 4G 200A alternators with custom cases. They have been awsome!

Well that's not good to hear, I run up to 6800rpm all the time.
Do you have a part# for the denso that is on the 2010's? may be able to cancel the vatozone purchase.
Damn you for posting late!

edit: all I see is motorcraft on rockauto for the 2010 gt.
Instead of bringing my stock alt in for the whopping $10 core refund!
Should I just get it rebuilt with quality parts and have it as a good backup?

 

[Department Of Boost]

I need to check to be 100% sure but I don’t think the Denzo is a direct plug in.

edit: all I see is motorcraft on rockauto for the 2010 gt.

Then what you see is wrong, I have never seen a 2010 without a Denzo.

 

[fdjizm]

Ok cool gotcha. I don't even know what 3g 4g 5g 6g means in alternator terms so no idea what the duralast one is.

 

[Department Of Boost]

Ok cool gotcha. I don't even know what 3g 4g 5g 6g means in alternator terms so no idea what the duralast one is.

4G, 5G, 6G is the design.

You could think of it as 302, 351, 460…..

Looks to me like “Duralast” is a brand name for a re-manufactured alternator, specifically AutoZone’s brand name. The “Duralast” process does not change what kind of alternator it is (4G, 5G, 6G, etc). It is just who is rebuilding it.

In regards to “Re-Man” facilities there aren’t that many out there. Most of the alternators that can be had from the chain stores come from the same few “Re-Man” operations in the US. A friend of mine owns one of them, that’s the only reason I know all of this.

It doesn’t matter who rebuilds it, the 6G is still a flawed design. We’ve rebuilt the 6G’s with the best of everything, by hand, complete attention to detail and made any improvements that can be made. Think of it as “blueprinting”. All that work doesn’t change a thing, they are still a crap design and can last anywhere from 5min to 5yrs.

Additionally these days 135A is not that much.

 

[fdjizm]

I opted for the duralast gold alternator vs a duralast alternator (gold is $20 more), it says it uses 100% brand new parts not re-man. (if that helps any)

What do you recommend as far as an alternator, you said the 2010 is not a drop in?
so what now lol

 

[06Torch]

My battery and Alt tested ok too. This is until the guy at Advanced Auto Parts had me put the high beams on, the radio real loud, and the A/C on high. Then the dashboard went nutz. I was able to get it limping home with almost every system light going on and off sporadically. By the time I got home, the car would turn on but the windows wouldn't go up.


Gerardo

 

[fdjizm]

^yea, none of that happened yet but I'm sure it's almost here so gotta get this alt in! lol

 

[Department Of Boost]

(if that helps any)

It doesn't.

What do you recommend as far as an alternator, you said the 2010 is not a drop in?
so what now lol

A 2010 will drop in as far as bolting up goes. But I am not sure if it plugs in, I don't think it does. We just started looking at these as an option and I need to do some more checking into it. I am hoping that if they need a different plug that we can make the required pigtails to make it happen.

Right now we have 4G alternators that are a real deal 200A that work fantastic. They require custom cases though and because they are slightly different in size they won't fit all applications. They fit most though.

They aren't cheap. They start at:

$375 with no pulley (you can re-use your own clutched pulley)

$425 with a brand new clutched pulley installed

My battery and Alt tested ok too. This is until the guy at Advanced Auto Parts had me put the high beams on, the radio real loud, and the A/C on high. Then the dashboard went nutz. I was able to get it limping home with almost every system light going on and off sporadically. By the time I got home, the car would turn on but the windows wouldn't go up.


Gerardo

As you just found out the “tests” that the auto stores do don’t do a very good job of telling you what is good/isn’t good. I see people do it all the time though, get told their stuff is fine and go looking for other problems they will not find.

The only way to test what is going on correctly is to test the alternator/batter while it is on the car, the car is heat soaked, everything electrical is on with a volt meter at the battery and at the alternator. It doesn’t matter what your alternator/battery is doing at AutoZone off the car, you don’t use it like that. It’s irrelevant. They need to be tested on the car where they are being used and under the conditions they are being subjected too.

First you need to know what the PCM is commanding the alternator to run at. The voltage gets bumped in a lot of “tunes”. For example my blue car is set at 14.4v.

You then test the alternator by running one lead of a volt meter to the B+ terminal on the alternator (the big wire) and the other lead to ground. It’s best to run the second lead to the engine ground on the chassis for this test. Does it read 14.4v? If so the alternator is good. Does it read 14.0v? The alternator is probably fine, it’s just hot and loaded up real hard and not spinning very fast at idle. Does it read 13.4v or below? If so you are lacking in alternator.

You test the battery (car running) across the pos/neg terminals of the battery. If your alternator is reading 14.4v your battery should be the same, or within a couple of tenths. If the battery is running the same as the alternator your battery is good. If the battery is reading low compared to the alternator you have a weak battery or a bad ground(s).

Alternators and batteries work as a team. One can make the other bad. Chances are that if one needs replacing the other does too. If they both need to be replaced and you only replace one you can quickly smoke the component you just put in.

Quick electrical/charging system fun fact:

The car runs its electronics off of the battery. The battery is charged by the alternator. The car does not run off of the alternator directly. If the battery has any issue the “throughput” of the alternator will not be what it is supposed to be and you will have problems. Don’t forget to look at the alternator, battery, cables and grounds as a system. If one thing in that system fails or deteriorates it takes the entire system with it.

Granted this is an extreme example but I just had to go through all of this on my blue car.

My blue car has a LOT of electronics:

Three 55gpm water pumps

Three 255lph fuel pumps on a return system (running all the time)

The factory radiator fan plus three more fans (one 16” and two 10”)

That’s a LOT of JuJu, especially at idle!

I have one of our 200A alternators. It is making good power, right at 14.4v where it should be. But I was seeing voltage as low as 12.7v at idle while sitting at lights. End up my battery which was “good” just couldn’t get the job done. I put one of the new Interstate billy bad @$$ batteries in and things got a LOT better. But not perfect. It stopped freaking my gauges/shift lights out and stopped throwing codes. But if all the fans were running, which they are most of the time sitting at lights it would pull the whole system down 1-1.2v. We ended up putting a slightly smaller custom clutched pulley on the alternator and bumping the idle to 1000rpm to spin the alternator faster at idle.

And this is a system with “double ought” battery cable and 2ga alternator/ground cables!

Obviously my blue car is running a lot more electronics than most. But the above is a good demonstration of how hard these cars are to charge. I’m beating the snot out of a 200A alternator. A 135A alternator (stock) wouldn’t stand a chance. 135A alternators aren’t real happy running the electrics on your basic FI setup. Let alone a weak 135A alternator/battery which is the case a lot of the time.

 

[05moneypit]

Not trying to jack your thread but I figure since you are getting some support maybe someone will have an idea for me.

I have had the same issue now for almost 5 years. "Check charging system" message and the battery light comes on within 20 seconds of starting the car.

I have had 2 different alternators on the car and 2 batteries and it is always there. Neither of the alternators have failed to charge the battery.

I use the PRP software and have gone in and changed the voltage parameters that determine if the alternator is good...set the low point to 10V and the high point to 15V and it made no difference.

The one thing I haven't tried yet is there is a PID in the software that turns off PCM control of the alternator. I'm a little afraid to try turning that off because I'm not sure what would happen.

It really isn't causing any problems but I would like to know why it it's happening.

The one thing that I have seen that is concerning to me is every once in awhile the generator duty cycle goes sky high. The screen shot of the data log below shows that.

I did have it to my local dealer a few years ago and they tested it and said it was the alternator. I put a new OEM alternator on and it still did it. Took the car back to them and they said to replace the PCM...which I'm not going to do.

Like I said sorry for jacking your thread but I figured there are already enough alternator problem threads.

Lee

 

[Department Of Boost]

Not trying to jack your thread but I figure since you are getting some support maybe someone will have an idea for me.

I have had the same issue now for almost 5 years. "Check charging system" message and the battery light comes on within 20 seconds of starting the car.

I have had 2 different alternators on the car and 2 batteries and it is always there. Neither of the alternators have failed to charge the battery.

I use the PRP software and have gone in and changed the voltage parameters that determine if the alternator is good...set the low point to 10V and the high point to 15V and it made no difference.

The one thing I haven't tried yet is there is a PID in the software that turns off PCM control of the alternator. I'm a little afraid to try turning that off because I'm not sure what would happen.

It really isn't causing any problems but I would like to know why it it's happening.

The one thing that I have seen that is concerning to me is every once in awhile the generator duty cycle goes sky high. The screen shot of the data log below shows that.

I did have it to my local dealer a few years ago and they tested it and said it was the alternator. I put a new OEM alternator on and it still did it. Took the car back to them and they said to replace the PCM...which I'm not going to do.

Like I said sorry for jacking your thread but I figured there are already enough alternator problem threads.

Lee

http://s763.photobucket.com/user/leesproshop/media/Alternatortest_zps52a03652.png.html

Is your battery in the trunk? Where is the battery grounded?

What are you using for a "distribution" point under the hood if the battery is in the back?

Is your alternator in the stock location?

Is the alternator painted/powdercoated?

 

[fdjizm]

Damn bro! thanks for all the info... still don't know what the fuckin ideal alternator is except for a custom cased 200a? lol awesome info though hopefully my vatozone deal works out for a few years.

 

[Department Of Boost]

Not trying to jack your thread but I figure since you are getting some support maybe someone will have an idea for me.

I have had the same issue now for almost 5 years. "Check charging system" message and the battery light comes on within 20 seconds of starting the car.

I have had 2 different alternators on the car and 2 batteries and it is always there. Neither of the alternators have failed to charge the battery.

I use the PRP software and have gone in and changed the voltage parameters that determine if the alternator is good...set the low point to 10V and the high point to 15V and it made no difference.

The one thing I haven't tried yet is there is a PID in the software that turns off PCM control of the alternator. I'm a little afraid to try turning thact off because I'm not sure what would happen.

It really isn't causing any problems but I would like to know why it it's happening.

The one thing that I have seen that is concerning to me is every once in awhile the generator duty cycle goes sky high. The screen shot of the data log below shows that.

I did have it to my local dealer a few years ago and they tested it and said it was the alternator. I put a new OEM alternator on and it still did it. Took the car back to them and they said to replace the PCM...which I'm not going to do.

Like I said sorry for jacking your thread but I figured there are already enough alternator problem threads.

Lee

I was just thinking you have a big OD damper right? If so that alternator is getting whipped! That may explain the spikes. A OD alternator pulley wouldn't be a bad idea.

 

[05moneypit]

Is your battery in the trunk? Where is the battery grounded?

What are you using for a "distribution" point under the hood if the battery is in the back?

Is your alternator in the stock location?

Is the alternator painted/powdercoated?

Battery in trunk. Grounded to welded in roll cage.......But I also at one time ran a seperate (1/0) ground cable direct from the battery to the engine block...... Made no change.

Battery feeds directly to the BEC on the fuse block.

Alternator is in stock location.

Had a powder coated alternator once but have the new OEM on it now.