# Alternator advice



## Johnny B (Jun 4, 2019)

If your a good mechanic, sure rebuild it. However, I wouldn't bother useless you are super low on money. If I were you I would buy a new one, it is the best way to ensure it lasts. Rebuilt alternators tend to be a dice roll. You can get an OEM alternator for half that outside the dealership.



More Information for GM GENUINE 84178065


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## Tomko (Jun 1, 2013)

Unsure how or why you’re diagnosing a faulty alternator?

Because of the charging strategy of the CTD’s electrical system, I’ve noticed that it doesn’t always keep the battery topped-off.

Many years ago I established a practice of putting an AGM-compliant charger on my battery every month.

I use a NOCO Genius G26000.


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## BDCCruze (Jul 12, 2017)

How old is the battery? The batteries fail around 5-6 years. Also, what type of battery is it?

Also make sure your negative cable is ran through the current clamp.


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## 15cruzediesel (Sep 30, 2019)

pacolino said:


> It seems like I have a bad alternator, car has 163,000km, I've (load) tested the battery and it seems like it passed the test. My only concern is how come it only measured 731cca when it's rated for 920cca (at 15C)?
> Now, a brand new alternator (at stealership) is $520 cad (part only), that's quite steepy, I would prefer to rebuild mine and not buying a new one, any advices in this regards?


If it starts, throws no codes and while running you see 13 or 14 volts initially there is no problem.

Internally there are several things that cause a battery to lose cca and it is normal as any battery ages. 

But most important is what you load tested it with. Is it know to be in calibration?


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## snowwy66 (Nov 5, 2017)

I'd like to know how he got his load results and made the determination.


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## Cruzing12 (Oct 10, 2020)

Fellow Canadian try rockauto.com . Often the prices are a third compared to even part source. But shipping is often the deal breaker around 35 flat rate through fed ex


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## revjpeterson (Oct 2, 2013)

I just ordered an OEM alternator on Rockauto last week for $152.79 US.


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## pacolino (Aug 1, 2015)

thanks for replies, I didn't expect to get so many honestly.
So here are my few answers to your questions:

"_Unsure how or why you’re diagnosing a faulty alternator?"_
you need to know which of the two (or both) is bad, the battery and/or the alternator? So things start going "down the ramp" recently like car having hard time to start. So I thought it's the EGR and the throttle valves, so I cleaned them nicely, including the map sensor. I didn't notice much of the difference, 'till a long trip (about 6 hrs) when car didn't start when we had a short stop at a Walmart along our way back. When jumped car starts right away and drives good with no issues.

"_Many years ago I established a practice of putting an AGM-compliant charger on my battery every month."_
So after that experience recently I've start using a trickle charger while at work so it will be fully charged when I leave work. It seems like it's keeping the battery happy that way.

"_How old is the battery? The batteries fail around 5-6 years. Also, what type of battery is it?_
the battery is just 1 year and 10 months old, it's a Motomaster Eliminator AGM size 94R, these batteries has 5 years warranty.

"_Also make sure your negative cable is ran through the current clamp."_
Yes it ran right through the current clamp and I checked all the connections, they're all rock-solid.

"_But most important is what you load tested it with. Is it know to be in calibration?_"
"_I'd like to know how he got his load results and made the determination._"
the battery was tested at Canadian Tire shop where they hooked it up to tester which seemed to be like a professional device then after the test they printed like a receipt which shows the test results: good battery, and the cca values I just put in my first post above.

"_Fellow Canadian try rockauto.com . Often the prices are a third compared to even part source. But shipping is often the deal breaker around 35 flat rate through fed ex"_
Thank you my friend, I've seen that at rockauto but I believe those alternators are rebuilt units, not new.

I will probably go with the deal Johnny mentioned above, for a $153 usd new unit you can't go wrong. Thanks again.


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## Tomko (Jun 1, 2013)

Suggest that you make sure the trickle charger that you’re using is compliant with AGM batteries.

AGM require a higher voltage than normal flooded cell batteries. Using a non-AGM charger will sulphate an AGM battery. Whereas an AGM charger will boil a flooded cell battery.

A trickle charger is better than nothing. But even my 26 amp NOCO can take three or more hours on my battery once a month. Suggest you look at the 10 amp NOCO genius. I wouldn’t go smaller than that on a CTD’s battery.


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## Cruzing12 (Oct 10, 2020)

pacolino said:


> thanks for replies, I didn't expect to get so many honestly.
> So here are my few answers to your questions:
> 
> 
> ...


More Information for GM GENUINE 84178065


rockauto has their used, new, and performance parts color coded. blue is new, Orange is their used, remaned, or economy section, and Red preformance/ heavy duty ... non the less 200 cad plus shipping.


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## 15cruzediesel (Sep 30, 2019)

Sounds like your alternator is working hard to keep a marginal battery charged to me.


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## pacolino (Aug 1, 2015)

Tomko said:


> Suggest that you make sure the trickle charger that you’re using is compliant with AGM batteries.
> 
> AGM require a higher voltage than normal flooded cell batteries. Using a non-AGM charger will sulphate an AGM battery. Whereas an AGM charger will boil a flooded cell battery.
> 
> A trickle charger is better than nothing. But even my 26 amp NOCO can take three or more hours on my battery once a month. Suggest you look at the 10 amp NOCO genius. I wouldn’t go smaller than that on a CTD’s battery.


yes it is compliant with AGM, Gel and wet batteries, it's a "BLACK+DECKER BM3B Fully Automatic 6V/12V Battery Charger/Maintainer", it's only 1.2A, works hard but it's doing the job, it takes couple of hours to fully charge it, it gets hot at touch though.


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## pacolino (Aug 1, 2015)

15cruzediesel said:


> Sounds like your alternator is working hard to keep a marginal battery charged to me.


well that's not what the battery test results shows.


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## 15cruzediesel (Sep 30, 2019)

pacolino said:


> well that's not what the battery test results shows.


I'm just going by your original post.

"I've (load) tested the battery and it seems like it passed the test. My only concern is how come it only measured 731cca when it's rated for 920cca (at 15C)?"

Sounds like a marginal battery to me or your getting parasitic draw.


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## BDCCruze (Jul 12, 2017)

Try this. Get in the car and turn on the fan at full speed, heated seats on and defroster on. Switch the DIC to the voltage gauge or put a multimeter on the battery. It should jump up to 14v. If it's doing that then the alternator is working correctly.


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## Tomko (Jun 1, 2013)

pacolino said:


> yes it is compliant with AGM, Gel and wet batteries, it's a "BLACK+DECKER BM3B Fully Automatic 6V/12V Battery Charger/Maintainer", it's only 1.2A, works hard but it's doing the job, it takes couple of hours to fully charge it, it gets hot at touch though.


It’s not as well known as it should be, but “AGM, gel and wet batteries” all require their own unique charging strategy. Some chargers and maintainers are capable of doing all three. But none are capable of figuring it out on their own. Any that are truly capable require the user to manually select the battery type.

The B+D BM3B sounds something like universal transmission fluid. We’ve all seen it. But we all know that it’s for only the worst emergencies. And even then, flushed out with the correct factory fill ASAP.

I feel that the unit you’re currently using may be good in a pinch. But that in the long run is sulphating your battery and actually causing it to decline in capacity.

There‘s nothing wrong with a 1.2 amp maintainer. But there’s no way that it would ever bring your battery up to full charge in a couple of hours. It is likely that your maintainer is timing out after a few hours. Or shutting down for thermal protection.

Right now I have four x 1.25 amp Deltran Battery Tender Plus, an AGM compliant 4.3 amp CTEK (a GM suppler), an old-fashioned 6 amp charger, and an AGM compliant 26 amp NOCO (also a GM supplier). I know a little bit about chargers/maintainers.

If my 26 amp charger, set to AGM, requires up to three hours on my CTD’s battery once a month, think about what that means for a 1.2 amp that is less than 5% as powerful. Mathematically that works out to 72 hours, or three days at full 1.2 amp capacity. The reality, of course, would be much more than that.

My intent is to share information based on my knowledge and experience. Something that I’ve done here for more than nine years. And why most of us post our troubleshooting and best practices.

So, in summary, I don’t think that you need a new alternator, or battery. But I do think that you would benefit from a battery charger/maintainer specifically designed for AGM.


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## 15cruzediesel (Sep 30, 2019)

Tomko said:


> It’s not as well known as it should be, but “AGM, gel and wet batteries” all require their own unique charging strategy. Some chargers and maintainers are capable of doing all three. But none are capable of figuring it out on their own. Any that are truly capable require the user to manually select the battery type.
> 
> The B+D BM3B sounds something like universal transmission fluid. We’ve all seen it. But we all know that it’s for only the worst emergencies. And even then, flushed out with the correct factory fill ASAP.
> 
> ...


Excellent advice.
He did say the car has needed to be jumped started at times.🤔🤔

If I remember correctly my OG battery would do the same thing. Be OK and not OK from time to time.


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## pacolino (Aug 1, 2015)

so here is an update:
The issue was indeed the battery, it was a marginally dying battery. CT replaced it under warranty.
It is intriguing how come a 2 years old AGM battery couldn't make it any longer than that?!
Also what's interesting is for the past 6 months or so (while driving it with the old battery) I intermittently got P026C codes (I cleared them every time), don't know how many but they came every 300km or so. It was probably because the weak power supplying the injection system, that's my guess.
Car is running stronger now with the new battery and is back to "normal" mpg, less regens and free of codes.
The real charge test was when I installed the new battery on the car it was at 67% charged (brand new from CT shelf) and after driving it for about 30min it was 100% charged.
Topdon is a really good battery load tool for who ever needs one out there.


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## ChevyGuy (Dec 13, 2014)

Isn't our cars set up for flooded cell batteries? If so, it's probably not going to charge the AGM the way it wants to be charged. Unlike older cars that just put out 14.4V when running, the Cruze has a computer controlled charging system that monitors battery voltage and charge current. There are times I can be driving down the freeway and the voltage indicator is only 12V


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## Tomko (Jun 1, 2013)

pacolino said:


> so here is an update:
> The issue was indeed the battery, it was a marginally dying battery. CT replaced it under warranty.
> It is intriguing how come a 2 years old AGM battery couldn't make it any longer than that?!
> Also what's interesting is for the past 6 months or so (while driving it with the old battery) I intermittently got P026C codes (I cleared them every time), don't know how many but they came every 300km or so. It was probably because the weak power supplying the injection system, that's my guess.
> ...


Good on you for getting comped a new battery.

But regardless of Black and Decker’s marketing claims, my guess is that your AGM battery was damaged by the BM3B maintainer that you were using. Its ‘universal’ charging voltage was insufficient for your AGM, sulphated the plates, and depleted the battery’s capacity.

Not something that a CTC parts Johnny would pick up on.


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## pacolino (Aug 1, 2015)

Tomko said:


> Good on you for getting comped a new battery.
> 
> But regardless of Black and Decker’s marketing claims, my guess is that your AGM battery was damaged by the BM3B maintainer that you were using. Its ‘universal’ charging voltage was insufficient for your AGM, sulphated the plates, and depleted the battery’s capacity.
> 
> Not something that a CTC parts Johnny would pick up on.


well I disagree with you, the battery was long way damaged before even charging it with my trickle charger.


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## Tomko (Jun 1, 2013)

pacolino said:


> well I disagree with you, the battery was long way damaged before even charging it with my trickle charger.


I agree that your battery was definitely depleted of charge in the first instance. That’s why you placed that BM3B on it.

My guess is that the BM3B did the depleted battery no favours in that it’s charging voltage is below AGM requirements. 

Best of luck with your new battery. These CTDs are hard on their batteries in our climate. In two weeks my NorthStar will make five years of service. Hope it keeps on keeping on.


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## BDCCruze (Jul 12, 2017)

ChevyGuy said:


> Isn't our cars set up for flooded cell batteries? If so, it's probably not going to charge the AGM the way it wants to be charged. Unlike older cars that just put out 14.4V when running, the Cruze has a computer controlled charging system that monitors battery voltage and charge current. There are times I can be driving down the freeway and the voltage indicator is only 12V


Maybe the gasers are but the Diesel comes with an AGM battery.


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## pacolino (Aug 1, 2015)

Tomko said:


> I agree that your battery was definitely depleted of charge in the first instance. That’s why you placed that BM3B on it.
> 
> My guess is that the BM3B did the depleted battery no favours in that it’s charging voltage is below AGM requirements.
> 
> Best of luck with your new battery. These CTDs are hard on their batteries in our climate. In two weeks my NorthStar will make five years of service. Hope it keeps on keeping on.


well if the new battery will last another 2-3 years that should be fine but I will not buy another motomaster battery, lesson learned. Yes I would say diesels in general are hard on batteries, I also own a 2007 Jeep GC CRD which requires more juice and a bigger battery than CTD's. 
It is possible that the heat produced by the CTD engines could be a "killer" factor (in time) as well for an AGM battery. cheers


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## boraz (Aug 29, 2013)

pacolino said:


> well if the new battery will last another 2-3 years that should be fine but I will not buy another motomaster battery, lesson learned. Yes I would say diesels in general are hard on batteries, I also own a 2007 Jeep GC CRD which requires more juice and a bigger battery than CTD's.
> It is possible that the heat produced by the CTD engines could be a "killer" factor (in time) as well for an AGM battery. cheers


diesels run cooler than gassers


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## pacolino (Aug 1, 2015)

boraz said:


> diesels run cooler than gassers


I generally agree but not to this one, CTDs engine is so hot in the summer that you can fry egs on it...


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## pacolino (Aug 1, 2015)

Tomko said:


> I agree that your battery was definitely depleted of charge in the first instance. That’s why you placed that BM3B on it.
> 
> My guess is that the BM3B did the depleted battery no favours in that it’s charging voltage is below AGM requirements.
> 
> Best of luck with your new battery. These CTDs are hard on their batteries in our climate. In two weeks my NorthStar will make five years of service. Hope it keeps on keeping on.


haven't heard of NorthStar, where did you buy it, are those actually the Odyssey batteries?


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## Tomko (Jun 1, 2013)

pacolino said:


> haven't heard of NorthStar, where did you buy it, are those actually the Odyssey batteries?


IIRC NorthStar and Odyssey are now one company.

At the time I purchased the battery, Odyssey did not make a 94R battery. NorthStar was then the best AGM 94R available. And may still be. 

I bought it from my friendly neighbourhood Total Battery.


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