Weak battery or alternator?

RPDBlueMoon

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Yup, BCM only runs the alternator at the needed duty cycle for the car's electrical demands to save a tiny bit of fuel/wear. If your alternator is actually underperforming it will almost always set a code.
I wouldn't say this. I just had a bad alternator plaguing for my car for almost 2 years and it was the alternator underperforming and malfunctioning. I had no codes. I would randomly get the Charging System now error but it wouldn't stay on permanently, it would randomly pop up and and go away.

Wasn't until my alternator was really jacked up and it was causing my car to stall and make a loud electrical whining sound that I found out that the alternator was the source of all my problems.

Not saying that you don't know what you are talking about or anything just saying to not rule out the alternator :)

 

Demonic

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I wouldn't say this. I just had a bad alternator plaguing for my car for almost 2 years and it was the alternator underperforming and malfunctioning. I had no codes. I would randomly get the Charging System now error but it wouldn't stay on permanently, it would randomly pop up and and go away.

Wasn't until my alternator was really jacked up and it was causing my car to stall and make a loud electrical whining sound that I found out that the alternator was the source of all my problems.

Not saying that you don't know what you are talking about or anything just saying to not rule out the alternator :)
Curious if you had no soft codes also? The electrical systems on these cars have many soft codes that would never indicate anything on the dash or display.
 

RPDBlueMoon

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Curious if you had no soft codes also? The electrical systems on these cars have many soft codes that would never indicate anything on the dash or display.
Not sure what soft codes are, I don't own a Forscan tool so I don't know. The ODB2 I got is the Innova 5014 scanner. Thought maybe I could see some data or something that would jump out at me but it showed that everything was fine.

There were a few times that the dealership did tell me that they saw codes with the battery when I kept taking it in. They did a reset on the battery which I thought would fix the problems but it didn't. There were other times that when I took it in they didn't see any battery codes.
 

ice445

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I wouldn't say this. I just had a bad alternator plaguing for my car for almost 2 years and it was the alternator underperforming and malfunctioning. I had no codes. I would randomly get the Charging System now error but it wouldn't stay on permanently, it would randomly pop up and and go away.

Wasn't until my alternator was really jacked up and it was causing my car to stall and make a loud electrical whining sound that I found out that the alternator was the source of all my problems.

Not saying that you don't know what you are talking about or anything just saying to not rule out the alternator :)
I get what you're saying, but if you were getting the "check charging system" or another related message on the dash, there was definitely a code being tripped, but it was probably "pending" and the condition corrected itself before it got passed down to the check engine light or to your scanner when you plugged it in to check. Engineering test mode can sometimes see those hidden DTC's.
 

RPDBlueMoon

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My 350 has developed a slightly different set of symptoms that seem alternator/battery related. It began with intermittent display of a “Charging System Service Now” message but no other symptoms. Both the battery and the alternator got a clean bill of health from a Parts Store check. My Indie mechanic examined it and couldn’t replicate the problem.

It was good for several days. But then it returned and got much worse. The message became much more frequent, the volt meter was all over the map on the high side (14-15-16 volt readings).

Thinking that the battery on my 2019 with 11K miles was the likely culprit and being on the road 4 hours from home on a Sunday afternoon we threw a new battery on it. And we reset BMS. No change. Eventually it started shutting down systems (interior lighting, infotainment, climate control, power steering). Volt meter still jumpy and showing lots of high readings.

One quirk is that the symptoms are dramatically reduced at super slow/parking lot/stop&go speeds.

I have a Ford dealer service appointment for next week, but I’m curious if anyone here has seen this before.

At this point my thinking is either bad alternator or a bad/loose ground wire somewhere.
I had very similar problems. I would have systems shut down randomly. It was like an EMP hit my car it was super weird, and a few times I almost crashed because I couldn't turn my wheel when driving. Very scary. Eventually those random shutdowns stopped and then I had problems where the car wouldn't start. I'd have to try 2-3 times or even 9 times and it would just start up like normal and be fine.

Like you I had problems with getting the issues replicated. Every time I took it in the problems never showed up so it was frustrating. I thought it was the battery, I bought the Odyssey AGM battery and reset the BMS. I thought it could be the alternator but the service tech dismissed that. So when I started having problems with the car stating I thought it was the starter or maybe it was a wiring problem. Was getting really scared and thought maybe something was seriously fucked up with my car and I got a lemon. I got annoyed having to go back and forth (this was a 2 year process) and I decided to just let the car just break completely and just tow it to the dealership and let them fix it

Eventually it started to make this loud whining sound at idle like it was supercharged, and it would cause my car to stall when I gave it some revs (even though Id be in neutral). Happened every time when the car started and it was blatantly obvious, so thats when I got it towed. They replaced the alternator and all of the issues went away. I have videos of these issues happen if you want to see them, but it'd start with the alternator and press to get it replaced. Mine was "malfunctioning" but it wasn't dead.
 


ice445

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I had very similar problems. I would have systems shut down randomly. It was like an EMP hit my car it was super weird, and a few times I almost crashed because I couldn't turn my wheel when driving. Very scary. Eventually those random shutdowns stopped and then I had problems where the car wouldn't start. I'd have to try 2-3 times or even 9 times and it would just start up like normal and be fine.

Like you I had problems with getting the issues replicated. Every time I took it in the problems never showed up so it was frustrating. I thought it was the battery, I bought the Odyssey AGM battery and reset the BMS. I thought it could be the alternator but the service tech dismissed that. So when I started having problems with the car stating I thought it was the starter or maybe it was a wiring problem. Was getting really scared and thought maybe something was seriously fucked up with my car and I got a lemon. I got annoyed having to go back and forth (this was a 2 year process) and I decided to just let the car just break completely and just tow it to the dealership and let them fix it

Eventually it started to make this loud whining sound at idle like it was supercharged, and it would cause my car to stall when I gave it some revs (even though Id be in neutral). Happened every time when the car started and it was blatantly obvious, so thats when I got it towed. They replaced the alternator and all of the issues went away. I have videos of these issues happen if you want to see them, but it'd start with the alternator and press to get it replaced. Mine was "malfunctioning" but it wasn't dead.
Haha, I bet you the bearing was melting down near the end. If you had touched the casing you probably would have gotten burned instantly. I've seen some fun alternator failures like that. In the case where the alternator can output properly (from an electrical standpoint) but the bearing is excessively worn/failing, I could see that really confusing the car because it will require more engine load for a given output than it should. The car will know something isn't right, but probably won't be able to really figure out what exactly.

Worth taking the belt off and checking the alternator pulley for excessive drag if you're having weird issues like that. Of course, if you're expecting parts throwers at the dealership to do anything more than what the computer tells them, you basically have to do what you did. Which is wait for melt down, lol.
 

Egparson202

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I had very similar problems. I would have systems shut down randomly. It was like an EMP hit my car it was super weird, and a few times I almost crashed because I couldn't turn my wheel when driving. Very scary. Eventually those random shutdowns stopped and then I had problems where the car wouldn't start. I'd have to try 2-3 times or even 9 times and it would just start up like normal and be fine.

Like you I had problems with getting the issues replicated. Every time I took it in the problems never showed up so it was frustrating. I thought it was the battery, I bought the Odyssey AGM battery and reset the BMS. I thought it could be the alternator but the service tech dismissed that. So when I started having problems with the car stating I thought it was the starter or maybe it was a wiring problem. Was getting really scared and thought maybe something was seriously fucked up with my car and I got a lemon. I got annoyed having to go back and forth (this was a 2 year process) and I decided to just let the car just break completely and just tow it to the dealership and let them fix it

Eventually it started to make this loud whining sound at idle like it was supercharged, and it would cause my car to stall when I gave it some revs (even though Id be in neutral). Happened every time when the car started and it was blatantly obvious, so thats when I got it towed. They replaced the alternator and all of the issues went away. I have videos of these issues happen if you want to see them, but it'd start with the alternator and press to get it replaced. Mine was "malfunctioning" but it wasn't dead.
Thanks for posting this. It seems to be a less common variation of a charging system issue. Do you recall what your voltmeter readings were when it was malfunctioning?
 

RPDBlueMoon

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Haha, I bet you the bearing was melting down near the end. If you had touched the casing you probably would have gotten burned instantly. I've seen some fun alternator failures like that. In the case where the alternator can output properly (from an electrical standpoint) but the bearing is excessively worn/failing, I could see that really confusing the car because it will require more engine load for a given output than it should. The car will know something isn't right, but probably won't be able to really figure out what exactly.

Worth taking the belt off and checking the alternator pulley for excessive drag if you're having weird issues like that. Of course, if you're expecting parts throwers at the dealership to do anything more than what the computer tells them, you basically have to do what you did. Which is wait for melt down, lol.
Yeah there was also a really bad burning smell, kinda like burnt rubber, but it also give off the smell like I was burning the clutch, so that could be the heat you are talking about. I forget to mention this but it would only stall if I gave it some revs. When it would idle you would hear the sound and it would get louder as you gave it more gas, but whenever you went above like 3-4k RPMs, the RPMs would fall bellow 1k and would stall. But before it stalled it would make this gear grinding noise. I think it would still stall and make the noise even with the clutch engaged. It really freaked me out at first because I honestly thought now my clutch or transmission was done for because of my aggressive downshifts 😅 The AC system makes a similar noise too whenever I turn it on and it gets louder as I rev it, but its not nearly as loud as what the alternator was doing.

I don't really know too much about this stuff so I was really at a loss. I did move so I started seeing a new dealership that was better but they just couldn't replicate the problems I was having because it was so random. I did tell the new service advisor that I was done taking it back and forth and was just going to drive it hard until whatever is broken just completely breaks . He got a chuckle from it and just said they'll be ready for it lol. So much for being proactive 😆
 
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RPDBlueMoon

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Thanks for posting this. It seems to be a less common variation of a charging system issue. Do you recall what your voltmeter readings were when it was malfunctioning?
So when it would do the random glitch stuff I didn't really pay attention to the voltage. There was one time that it did happen regularly and I didn't see the voltage change drastically. Another problem I had too is that the infotainment screen would go black randomly and do this:

1661354585374.png


I even had this before:


1661354659858.png


With the most recent problem when it was making that really bad whine the voltage readings were 12.1V and 11.4V.

I did digging through old posts when I was trying to figure out the problems I was having and I remember people saying that the inboard voltage reading isn't accurate and can give false positives and negatives. So I didn't really pay attention to the readings. Today I put on some good miles today and I say it hovering at around the high 13s.

Only thing that sounds like my situation is different than yours is that it didn't happen at low speeds mostly. I've had it happen at all speeds and it was random. When the battery codes were reset the mostly fixed the random EMP stuff but then it just wouldn't turn on. One time I was on the phone with a tow truck because I tried starting it like 10 times and was getting the error that I exceeded the crank limit, and it suddenly just turned on after a 5 minute break. I swear it was so annoying dealing with this bs lol
 
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What is a good scan tool for the these cars?
 

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Put the Shelby in the shop this morning. Service Advisor listened and wrote it up. Said simply, “I have no idea how long this is going to take “.
 

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Just heard from Service Advisor. The car has a bad wire and connecter to the alternator that has to be replaced and rewired. Thought it might be heat related. Anyway, they have to order the part. Probably gonna be mid-week, and that’s fine. We’re headed out for a weekend of camping, and I’ll have a healthy car for the early-October event @ CMP with CRMC.
 

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What is a good scan tool for the these cars?

OP: I have the same question. I’ll try to find out something on this when I pick up the car. My scan tool didn’t have any codes even though the car was going crazy.
 

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Kind of strange the dealership replaced the battery before selling the car. I guess it sat and they didn’t maintain it. I bought my ‘19 new in June of 2020. If they replaced the battery, it wasn’t recorded. Car had 140 miles on it.
I live in a desert climate with intense heat in the summer, deadly on batteries. Our Subaru goes through Interstate batteries every four years like clock work. My Dodge Diesel 2500 work truck, every three years.
I guess it’s time to use my Ford rewards points to get a new battery. Hopefully I can trust the local dealership to do that.
Well I didn’t take my own advise soon enough. Dead battery this morning. It’s on a trickle charger and will be headed to the dealership for a battery replacement under warranty.
A close friend, who is a shop foreman at a MB dealership told me one of his old techs is the shop foreman at our local Ford dealership now. I feel better about taking my car in now. 😉
 

 
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