Hi all. I'm new to this forum so please forgive me if I'm not doing something correctly. Let me start off by saying I don't think I've made it more than a single oil change without having to work on my Maxima.


I bought it in August 2017. It presently has 150.3k miles on it. Battery reads 12.71 V cold and was new in 2016. No issues with starting normally except an occasional stutter. Only using 98 oct gas.

I don't know how many of these symptoms are connected to each other, so I'm just gonna kinda shotgun it and hope I'm pretty on-target.


The car sounds really bad when running. Very noisy whirr from the passenger side under the hood. Seems to come from alternator/power steering pump. I used a stethoscope on the alt and couldn't hear anything. Alternator does look a little extra black. I'd use the stethoscope on the power steering pump but I like keeping my face on my skull lol. PS fluid level is fine, though, and has been for 2 years. Haven't had to add any fluid, haven't drained it. Also at random times around 3500 RPM there'll be a weird whistle/chime that dissipates around 2.5k/4k RPM.


Onto the weirder issues. Once while in a drive thru, the car just cut off completely. I also have an occasional flicker on the high end of my speedometer where the light will occasionally die and come back. Also seemingly at random the brake and battery lights will flash on and off and random intervals. This doesn't seem to be related to engine speed, vehicle speed or brake use. Then a few weekends ago, my SES light comes on, followed by the ABS light. Then my AC stops blowing, dash lights turn off, and the vehicle stops accelerating. This happened again yesterday, and my speedometer was stuck at zero while the tachometer was reading about 3k rpm. If I decelerated, the tach would still be in the same area. Accelerating to 55 mph didn't really change RPM at all. It probably took 2 minutes of pedal-to-the-floor to even get up to what felt like 55 mph. Have also found out that during these issues, one of my headlamps went out (until I turned the car off and back on). All fuses are in tact and seated properly. Can't find any loose harnesses.


SES code was P1574 ("vehicle speed sensor signal"). Being that the ABS light came on, though, I decided to check those sensors with a multimeter. I got the front two out long enough to find out my multimeter probes were too big to test them lol.


Kind of at a loss. I can replace the alt but it's just a matter of knowing that that's the problem. On top of that, I don't know which speed sensor is malfunctioning (or there only one on the vehicle?). Also, how could I go about diagnosing that noise around the passenger side? It's like a low growl that gets louder with engine speed.

 

Although I did not read the entirety of your post with a great deal of attention to the details, I will tell you that the illumination of the brake dash indicator and the battery dash indicator together, typically is notification of an alternator failure.

 

That's the primary thing I've read. But there are no other indications of an alternator failure. Afaik, it's still the OEM alternator though, so after 150k miles it's super possible that's the case. I've seen other people on here indicate the same behavior of the lights and they've said that upon replacing the alt they still had the issue.

 

Then you need to do some charge system testing ...

 

I have. That's how I know that the only issue is the lights. Nothing else indicates alt'r problems

 

Well, if you have, then you would have told us the voltage reading on your multimeter with the car running with all accessories on...

Do this and report back. Make sure your AC is on, headlights etc at idle and report back what voltage reading you are getting at the battery.

 

Mostly commenting here in case someone comes here in the future looking for answers. It was my alternator. A loud whirr like a really bad vacuum cleaner that increased with motor speed coming from the passenger side of the car, brake+battery lights flashing at random, instrument cluster powering off, losing control of AC, radio power outage, no acceleration, etc. All the alternator. My car finally died the other day and when I attempted to crank it back up it was just a tick/rattle and no turn over. Battery was dead. Replaced the alternator and it runs like a new car.

 

Was my fix too when those light came on. New alt.