Alternator issue

[Mr.D]

I just noticed today while driving that the alternator will go from 14.5v to 13.1v and sometimes get as low as 12.7v, then suddenly jump back up to 14.5 for a while then drop down again. Battery is a new XSpower D3400R, I tested the voltage when I got home with the car off and the resting voltage is 13v. Is this a sign my alternator is going out?

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[Dafaseles]

I just noticed today while driving that the alternator will go from 14.5v to 13.1v and sometimes get as low as 12.7v, then suddenly jump back up to 14.5 for a while then drop down again. Battery is a new XSpower D3400R, I tested the voltage when I got home with the car off and the resting voltage is 13v. Is this a sign my alternator is going out?

Could be, or it could be done kind of voltage regulator within the car. For example, my truck when I start it will be at 14.7, then drop to 13.8ish, then, when the battery needs a bump, it can jump up to 15.3ish. And that's normal. They do it for added fuel economy.
What kind of car is it and what year?

 

[Mr.D]

Could be, or it could be done kind of voltage regulator within the car. For example, my truck when I start it will be at 14.7, then drop to 13.8ish, then, when the battery needs a bump, it can jump up to 15.3ish. And that's normal. They do it for added fuel economy.
What kind of car is it and what year?

Thanks for the reply. It's a 2014 infiniti Q50. This happens with the sound system completely off

 

[Bobbytwonames 5,000+ posts]

Thanks for the reply. It's a 2014 infiniti Q50. This happens with the sound system completely off

You might need a new tensioner pulley. My mechman was squealing like a bitchh when I started my truck. And it took a couple of minutes to stop squealing and raise the voltage up to a decent level. I changed the tensioner pulley and everything is golden now.

 

[Mr.D]

You might need a new tensioner pulley. My mechman was squealing like a bitchh when I started my truck. And it took a couple of minutes to stop squealing and raise the voltage up to a decent level. I changed the tensioner pulley and everything is golden now.

Possibly new belt too?

 

[Dafaseles]

Thanks for the reply. It's a 2014 infiniti Q50. This happens with the sound system completely off

Yeah, mine does it on its own also, no music or anything. It's just a factory thing they use to save fuel and bring up their fuel economy.
Do some digging around the internet, maybe find an infinity forum or Facebook group and ask people who now those cars inside and out. A lot of newer cars, such as yours, do things like that normally.
If it isn't normal, than yeah, it might be going out, or your pulley might not be spinning correctly. It's worth looking at.

 

[Mr.D]

Yeah, mine does it on its own also, no music or anything. It's just a factory thing they use to save fuel and bring up their fuel economy.
Do some digging around the internet, maybe find an infinity forum or Facebook group and ask people who now those cars inside and out. A lot of newer cars, such as yours, do things like that normally.
If it isn't normal, than yeah, it might be going out, or your pulley might not be spinning correctly. It's worth looking at.

Yeah I saw something about that. I also posted in a Q50 forum just waiting for their input. Kinda ***** for someone trying to have a subwoofer system if the xar regulates the viktage whenever it wants to

 

[Dafaseles]

Yeah I saw something about that. I also posted in a Q50 forum just waiting for their input. Kinda ***** for someone trying to have a subwoofer system if the xar regulates the viktage whenever it wants to

I agree, but it could be worse, you could have a BMW lol.
Car companies don't care about us aftermarket stereo system guys because 95% of the people who are going to buy the car won't install an aftermarket system. They'll be wowed by the stock system because "it gets loud enough for me" and it plays into the 40 hz range at low volumes lol. Unfortunately, this is the new normal. But there's usually a fix... sometimes it's not worth the hassle or the amount of money you have to spend, but there's usually a fix.

 

[Kickstand Premium Member]

I have a 2015 Q50s
Mine does the same thing
The whole car is one big computer so what your seeing are different accessories kicking in and out
Put it in ECO mode and watch what happens while it's regulating the output on the engine
I would love to see what the voltage is like on something like a 918
The whole car is adaptive and constantly adapting to your driving style

 

[Mr.D]

I have a 2015 Q50s
Mine does the same thing
The whole car is one big computer so what your seeing are different accessories kicking in and out
Put it in ECO mode and watch what happens while it's regulating the output on the engine
I would love to see what the voltage is like on something like a 918
The whole car is adaptive and constantly adapting to your driving style

If this is the case I'm ready to downgrade my system because no point in having such a large system if it's gonna do this crap

 

[mastershake575]

If this is the case I'm ready to downgrade my system because no point in having such a large system if it's gonna do this crap

No you need to find out how to bypass it. Here's some information on the Nissan based voltage regulators http://www.nissantechnicianinfo.mobi/htmlversions/2016_Feb_March_Issue_6/VoltageControl.html

Since your car stereo system isn't directly tied to the cars computer system there's nothing telling the alternator and it's sensor (ECM) to kick on.

I would contact Singer alternators https://www.singeralternators.com/ He's really good at tricking OEM alternator regulators. On most car models he will sell an adapter kit that's easy to install (the adapter basically tricks the ECM into thinking that the car needs a maximum power/voltage draw at all times).

On some car models there's also the possibility of being able to turn it off somewhere else under the hood (for example on my old honda I could disable the voltage regulator by unplugging it from the main fuse box)

 

[Mr.D]

No you need to find out how to bypass it. Here's some information on the Nissan based voltage regulators http://www.nissantechnicianinfo.mobi/htmlversions/2016_Feb_March_Issue_6/VoltageControl.html

Since your car stereo system isn't directly tied to the cars computer system there's nothing telling the alternator and it's sensor (ECM) to kick on.

I would contact Singer alternators https://www.singeralternators.com/ He's really good at tricking OEM alternator regulators. On most car models he will sell an adapter kit that's easy to install (the adapter basically tricks the ECM into thinking that the car needs a maximum power/voltage draw at all times).

On some car models there's also the possibility of being able to turn it off somewhere else in the car (on my old honda I could disable the voltage regulator by unplugging it from the main fuse box)

That would be great if I can do that. I will definitely contact him. Thank you