What brand of alternator did you install? Your original was probably bad even though it measures good when you check it for a few seconds now. So many of these alternators go out of regulation intermittently and cause the symptoms you're observing. I suspect you have another one crapping out intermittently on you now. I installed a Bosch reman in my 2nd gen a year ago after my original oem failed intermittently and stranded the previous owner and myself multiple times. So far so good but many stories here about store brand alternators failing out of the box or shortly thereafter.

You could check your alternator connector to be sure the connector isn't brittle/cracked and the contacts aren't burnt inside the connector and therefore making crap contact. Maybe monitor the charging system voltage while you wiggle the connector and see if it changes. The first thing the Nissan factory manual tells you to do when debugging the charging system is to disable the variable voltage control of the alternator by disconnecting the current sensor on the negative battery cable so the charging voltage is predictable at maximum (14.1-14.7) and won't be reduced by the control system. If you wiggle the alternator connector and you get the charging voltage to drop out, it could mean the problem is in the harness/connector and not the alternator.

Download the factory service manual if you haven't already. There's a troubleshooting tree in the chapter for the charging system that will tell you what to measure at all the pins on the alternator to determine which piece of the system is bad. You sound like a handy diy type if you have a scanner and you're driving around monitoring your charging voltage. You could disable your variable voltage control to see if it would help. It may not help but it doesn't hurt anything other than make your car charge like a 1st gen and it takes one variable out of the system. I disabled this in my car during my alternator debug and left it disabled even after replacing the defective oem alternator just because I prefer simple over complex. They had to put extra switching components in the alternator to make it perform this function and it's just more things to fail unnecessarily in my opinion. This isn't a popular opinion around here but what have you go to lose at this point.... keep your battery charged up with an external charger while you're debugging this to avoid getting stranded if it konks out on you which it probably will until you figure out the source of the problem. Good luck.

Here's some other recent threads to read through all with 2015s with intermittent alternators causing symptoms like yours:

https://www.nissanmurano.org/threads/2015-murano-keeps-stalling.228983/?post_id=788562#post-788562

https://www.nissanmurano.org/threads/2015-nissan-murano-sudden-power-loss.228682/?post_id=788424#post-788424

https://www.nissanmurano.org/threads/2015-nissan-murano-looses-throttle-acceleration.228568/

 

UPDATE: Thank you for the helpful response. I'm beyond frustrated with the whole process.

Back to Autozone today, had them retest the old alternator. It passed with the following:
Battery Volts - 13.5, 14.94, 15.40
Ripple Volts - .00, .28, 2.0
Lamp-on Volts - .00, 1.46, 8.0
Lamp-off Volts - 13.00, 14.22, 0.00
Rated Amps - 150

With old Alt, when i started vehicle cold, plug in voltage reader showed 14.2 at idle. After driving for 10-12 minutes (stop start driving) voltage drops gradually until less than 10v, then it limps.
With NEW Refurbished Carquest premium installed, under the same conditions above, cold start voltage reads less than 12v. This is also with a brand new battery just purchased last night. (so new alt and new battery).

Still searching for the solution and really don't want to waste any more money at Nissan garage until I know what to tell them to fix.

Last note FWIW: I didn't follow the suggested removal process. I removed the AC unit from below the Alternator and pulled it out from the passenger side wheel well.

 

I mentioned this to someone else recently, since there was a thread from (I think) a few months ago where the fusible link on the positive battery wire was melted or corroded or something. Perhaps that fuse cluster is overheating and failing after a certain amount of time, making the battery unable to be charged. After sitting for a while, maybe there's enough juice to restart the car and the battery begins charging again until the fusible link becomes too hot (from the engine bay, from the wiring???) which triggers something within it to not allow current from the alternator, so battery reserves go low again. Maybe a take a close look at that area.

If nothing else, I'd say that heat or vibrations might be at play here. From what is the big question.

 

That's how I replaced mine as well so shouldn't be a problem as long as you hooked everything back up correctly and didn't break anything like the alternator wire harness during the removal/installation process. Did you look at that connector when you had it apart to be sure the contacts were in good shape? My connector was brittle as hell and the latch broke when I disconnected it. But the insides were ok.

Sounds like your new (refurb) unit is 100% not charging ever not even briefly after startup. Either the refurb carquest alternator is bad or you could have a problem in your harness that doesn't power the internal regulator properly. You're going to have to follow the troubleshooting flow chart to measure the voltages at the alternator connector(s) to be sure it's your alternator or harness/connector. This is the flowchart for my 2nd gen. Your 3rd gen should be similar but you should download it to be sure. If you haven't downloaded the service manual, you can google nicoclub murano fsm and you'll get a link to follow to download it. You've got the NO CHARGING VOLTAGE path to follow. That means check if your battery light comes on when you're in the key on engine off state (push the start button twice without your foot on the brake). I assume it's going to come on indicating the internal regulator is capable of pulling the fault lamp to ground to turn the light on. Then check if the light is off when idling and off when at 3000rpm (i assume off both times as you don't mention the light being on). If off, check if the B terminal is at specified charging voltage. If not, replace alternator. I'd follow the low charging path too and check your S terminal though. If that wire is open, you won't get charging either. My complete guess with nothing to go on is that you have a dead alternator.

 

Also, I don't know what the 3 different test states are in the autozone test but 15.4V sounds too high. I'm surprised they declare this a pass. If you watch the video in one of those links, the guy diagnosing that Maxima sees (i think) 15V when the problem pops up. Might have been 17V. I can't remember. But the description of your original problem sounds really similar to many previous posts with bad alternators. I wouldn't put that one back in if you're considering that.... you could of course to be sure since you're doing the labor but I bet that alternator is as bad as all the others described here. And you wouldn't be the first person to replace multiple aftermarket alternators. There are posts where people have changed them 3 or 4 times. Unbelievable considering how much work that is.

 

@Precism After watching this video, I'm more convinced than ever that Nissan's variable voltage control is just bad. This guy monitors his charging voltage in a normal working car with no problems and there are times it drops to 12.4V. That's just too low to be regulating the output while the engine is running. I disabled VVCS in my 2nd gen while I was debugging my intermittent charging system failure because there are so many online comments about problems people experience with it enabled. It's also the first step in the factory service manual inspection procedure. I left it disabled even after I replaced the alternator because I just don't think whatever minimal improvement there is in gas mileage is a good tradeoff for the extra complexity of the current sensing and battery state of charge estimation and variable control of the alternator. I'll take simple over unnecessarily complex any day. You might consider trying to disable this during your next replacement and see if you have a different experience. There's a better video about how to do it in the Murano which has a different IPDM than this Sentra. This video just demonstrates the VVCS performance...

 

Thanks for all the great information in your replies. I've read and heard the same about after-market generators. Tried to save some money and it cost me. I'll be removing it, returning it, and replacing it with the OEM-recommended version.

I'm betting that the issue remains after installation of new one. But that's just my healthy dose of skepticism. I'll update when I know more.

Thanks again

 

Thanks for all the great information in your replies. I've read and heard the same about after-market generators. Tried to save some money and it cost me. I'll be removing it, returning it, and replacing it with the OEM-recommended version.

I'm betting that the issue remains after installation of new one. But that's just my healthy dose of skepticism. I'll update when I know more.

Thanks again

Was watching a YT video by "The car care nut" on alternators last night. His suggestion was to always use OEM alternators as non oem alternators can lead to a plethora of issues. Hoping your issues are resolved after the replacement.

 

The car care nut is awesome. Super Toyota master mechanic and really aligns with my sensibility for simple being better than complex. Rather than just be a fanboy for whatever Toyota does, he'll actually call them out when they follow everybody else and do the wrong stuff. Like his call for best LS sedan model is the 430 rather than the 460 because they just kept adding more useless complexity and it's actually made the platform worse for long term owners. Kinda like the VVCS for Nissan. Would be great if there was a Nissan focused channel with an expert like the car care nut is for Toyota.

 

this is a refurbished OEM alternator. Would you buy?

 

The common wisdom from the past few years is that an OEM alternator has a much better chance of working correctly than an aftermarket alternator. It's pricey for a rebuilt but it's probably a smart way to go.

 

Thanks for your response. I already learned from my first non-OEM installation (see thread). So, I know I'm ordering an OEM, but should I order the REFURBISHED one. Same MFR Thanks $350 for refurb, $522 for brand new.

Alternator for 2015 Nissan Murano | OEM Parts Online

nissan.oempartsonline.com

 

If Nissan sells it, then I'd take the cheaper option. For $200 I can change an alternator again if needed.

 

Worked on my Murano with a mechanic friend last night. Ran diagnostics (manual style) and found 2 wires on the 3-pin connector were separated. Replaced connector and voila. 14.3v at startup, maintains 13.4ish driving. Put a few miles on with all accessories I could turn on and there was negligible difference.

Now that I've been through the Murano Alternator replacement hell, I'll share what I've learned: (keep in mind I'm NOT a mechanic)

1. Work with someone who knows more than you do about vehicle electrical issues.
2. Before assuming you need a new alternator, check your wiring harness. Had we seen the broken wires hidden down there, I could have save a lot of time and money.
3. IF you have to remove/replace your alternator, choose the passenger wheel well side vs taking it out from the top. This method also means you don't have to drain your radiator.
4. BUY AN OEM ALTERNATOR!!!!!!!

Thanks again for all the helpful answers. Now on to replacing Sensor 2, Bank 2 O2 sensor . Any

 

I had a similar experience,except i replaced the alternator before finding the bad control connections. Basically, i was left to wonder whether or not it needed a new alternator itself. I had to replace the harness connection as well.

I purchased a duralst gold alternator and its running like a champ. Has been for over a year now. We may not be experiencing the same issues we once did with aftermarket alternators. Esp. When we may be getting a mix of problems like we are with the harness in question as well.

Im happy you got this squared away. Who would have thought it would take so much for an alternator. All's well that ends well.

 

Great update. So did you end up replacing the alternator again or debug the existing replacement that was in the car and realize it's working if you fixed the harness?

 

We kept the new refurbished one that we originally installed in there and returned the OG alternator. Figured at 170k miles it was better to have one with lifetime warranty. Harness should be first thing to check. Good luck!