2011 maxima, ~220k miles but transmission was replaced around I'd say 170-180k (rough estimate..)

We just got the car a few weeks ago, replaced the struts, shocks, and sway bar end links (not used to sedans, do they always feel this bumpy or do I suck at working on cars haha)

So the symptoms I have are that the car loses power, to the point where we move at a snail's pace at barely 1000rpms.

The traction control light comes on, then abs lights, then the car shuts down. Won't start after that. If you jump it, it just shuts down again. If we charge the battery then put it back in it runs. Battery at 12.5 alternator charging to 14.4 while car runs.

Both battery and alternator have been replaced in the last couple months, both new. Any idea what it could be?

 

Sounds like the alternator is actually not charging the battery...or even running the car. Then when the battery is empty, she is done.

You said the alternator is charging...but is it actually running the car and charging the battery?

 

So, the voltage looks good. We tested it with the terminal off the car for a few seconds and the car ran smooth.

First time was a loose positive terminal, a good squeeze with pliers and light tapping and tightening the bolt got it k. The post.

Ran for a week until it died again.



One time it died as I parked, wouldn't start, and then the next day it started fine.


Anything it could be outside if alt and bat?

 

I wonder is there is something going on with the fuse pack at the positive terminal of the battery. Or maybe some mice got in the engine bay and had a field day with some wires. You're probably gonna have to get in there and inspect the wiring a bit, for it seems like something is lose, or something, since it is an intermittent issue.

Hopefully someone else here will be able to give you some direction.

 

Fuses (metal and fusible links), both seem good. What wires should I look at? I tried to find the wire from the alternator to the battery on nissans parts website but couldn't.

 

I wonder if it is a ground issue? Considering the age of the car, I would pull the battery/battery tray out and look and see what the connections of ground strap look like. I think there are two points where the negative ground strap connects to the body of the car.

 

An oldie but a goodie -

 

Take your car to Auto Zone and have the engine fault codes read. The codes will tell you what is going on.

 

I checked my codes and they were all clear except a permanent/archived p0102 (ran car with maf disconnected temporarily). Autozone load tested my battery and alternator and said both were good. Multimeter says same thing too. Car literally just dies out of nowhere. Battery gets drained while driving. If I take the battery out and take it to AZ to charge it, then put it back in, the car lasts for about a week before it happens again. Any ideas?

 

It's the wiring from the alternator. Same issue for me some months ago. Had my alternator changed first and it did the same thing. Took it to another mechanic and he noticed the wiring from the alternator was bad.

 

do you have a link for the whole cable? I cant find it

 

Checked the cable, was pretty much perfect outside of a little corrosion on the transmission ground. cleaned it up and replaced the bad positive terminal, still does it. New battery as well

 

Sounds to me the pwm signal is getting toasted when hot. Obviously to validate we need a scope and or decent scan tool but I would think it is bad wire, bad ecm or bad ignition switch. Take a drive for 20 or 30 mins and then check voltage and lets see if it is heat (if so probably ecm.) But personally, i think a bad pin in the connector (maybe pushing connector for pwm or has the connector spread during a replacement that was third party alternator) I just havent seen ecms go bad on 7th gens.

Remember to check after runnimg while hot and report back with voltage readings.

 

So the positive terminal wasn't covered by the boot. I covered it. Don't think that was the issue, I'm just waiting for it to die again. What do you think?

Also what's the pwm? I also haven't been able to find the whole wiring for the alternator.

 

Sorry, PWM stands for Pulse Width Modulation. It controls your alternator output. Some refer to this as Duty Cycle. The ECM (engine control module) varies the width of a square wave going to your alternator to control the current to the windings to vary the magnetic field thus impacting the output voltage.

This is why a scope is needed, to validate this is working.

Another check you should perform is the grounds.

Alas, testing voltages should always be done with a load. Turn on your lights, fan on high, defroster, wipers etc. You shouldnt see more than 0.5v difference.

Also, test the cable from the B+ to the battery by measuring between negative terminal on battery to positive...remember that reading. Now leaving the negative lead on the battery, put the positive lead on the B+ connector on the altermator. Shouldnt be.more than 0.25v difference.

The cap wont affect anything unless your battery isnt secure. This helps stop inadvertent shorts to ground and reminds folks jumping a car that it is the positive post.

Re good diagrams
Check out the Factory Service Manual (I believe The Wizard has a link im his signature box.

 

Any solution to this problem? I'm having the same issue.

 

Anyone know the name of the battery cable harness for a 2009 Nissan Maxima. I think/thought it was called the EGI Harness. Also, is this cable what connects the alternator to the battery. I'm trying to order parts so I can have a mecha ic install. But want to make sure I'm getting the right stuff.

 

Before paying $750.00 to $1200.00 for that harness you may want to invest in one of these power adapter voltmeters that you can plug in and check voltage thruout the drive cycle. If you are driving and see that your voltage is dropping, you can be relatively assured that it isn't the cable. Battery or Alternator to be sure. But I still maintain your scope would be your best bet.

 

Can you explain how watching the cigarette lighter voltage meter would assure me that it's not the Cable Harness assembly failing?? Trying to understand. Thanks in advance.

 

It can give you real-time voltage readings inside the car. If the voltage is fine at the Lighter, then it isn't the cable assy. If it is 14 v first thing in the morning when you start driving and then eventually goes down, it isn't the cable. Plus the voltage drops would be quite evident first thing in the am.

 

Alternator fuse on the positive battery cable

 

Can you tell me if you know this is the problem or if you are just making an educated guess? My car is having the same issues, and we checked all of the fuses on the positive battery terminal and they are good..my alternator tested good but when disconnected battery my car died immediately. Up until that point, I was certain it had to be in the wiring between the alternator and the battery (alternator not charging battery even though both are good) but now I'm scratching my head bc it seems as though it's between the alternator and the car..or maybe it has something to do with the alternators ability to send out voltage, like a voltage regulator issue..?

 

Do you have an aftermarket alternator??

If you do, that's your issue. We had an aftermarket alternator, swapped it with a used OEM and it worked perfectly. You can check your alternator for sure when starting your car after it dies when you jump it by checking if the battery light turns on then off. Apparently the alternator on the 7th gen Maxima's heat up and some aftermarkets can't handle the heat so they fail after a while.

 

I’m having same problem 09 maxima 250k has anyone figured out what’s wrong and how to fix

 

So the aftermarket alternator was your issue? My 8th gen is doing the same things you described.

 

Does anyone know what his solution was? My 2017 Maxima is doing the same things.