Sporadic Battery Charging System MIL

azshelby350

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When I was at the track about a month ago the large battery warning light came on indicating a charging system problem. The system was over-volting up to 15.99v so I had the alternator replaced and all was good. Took the car to the track again a couple weeks ago and had no issues. The last couple times I’ve driven the car on the street however the same charging system light comes on for a moment, then turns itself off. I’ve been monitoring the voltage gauge while I drive and don’t notice any real fluctuations, and the warning has come on during both easy and hard acceleration as well as while just cruising at freeway speeds. Is there some sensor that could be faulty?

 

JAJ

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When I was at the track about a month ago the large battery warning light came on indicating a charging system problem. The system was over-volting up to 15.99v so I had the alternator replaced and all was good. Took the car to the track again a couple weeks ago and had no issues. The last couple times I’ve driven the car on the street however the same charging system light comes on for a moment, then turns itself off. I’ve been monitoring the voltage gauge while I drive and don’t notice any real fluctuations, and the warning has come on during both easy and hard acceleration as well as while just cruising at freeway speeds. Is there some sensor that could be faulty?
If it's the 2016, then the battery could be a factor. If the 2019, then probably not. If it's not the alternator or the battery, then it's likely a wiring harness issue.

I had a similar warning last year at a track day as I was rolling off the track into the pits at the end of my last session. I drove carefully and monitored the voltage as I drove the 200 miles home. When I got home, I looked at the codes and nothing stood out, so replaced the six-year old battery. Next time on track, half a lap into the first session of the day, the warning came back. So, I took it in to the dealer and they replaced the alternator. One track day so far on the new battery and alternator and all is well.
 
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azshelby350

azshelby350

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@JAJ It’s the 2016, and the battery was replaced a few months ago. I doesn’t have any starting issues so I don’t think that’s the case.
 

barstowpo

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Mine did that as well. Dealer replaced the alternator under warranty and no problems since. With normal driving, the light stayed off. If I revved it out I could trigger the light almost on demand.
 

 
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