Free car! 03 Maxima GLE with charging issues.

[LeakySeals]

A neighbor gave us a free car! Its a first car for my GF's son who is about to get his license. 03 Maxima gle w/140k on the body. Used engine swap 40k ago, unknown miles. It runs (with a jump), moves. Sounds ok, no rapping. No CEL's. Low on oil, transmission fluid brown, etc. Will get to that. after I figure out why it won't hold a charge.

The story is the battery eventually loses charge, engine dies. Won't start unless jumpered. Runs for a bit, dies. The PO put in a new battery (looks cheap) and the new battery failed to hold a charge. He disconnected negative, car died instantly. Assumed its the alternator and gave up on the car.

Is disconnecting battery while running an accurate alternator test in a fairly modern car? I was going to try testing volts at battery while running to see if alternator is working so I had a battery tender junior on the battery all night. Still red (charging). Maybe the tender junior can't charge a car battery? Works good on my tractor..

All the fuses look ok..

The alternator is buried underneath engine so its not an easy swap. Probably why the car was given up on. Is it really the alternator? Or just a cheap [censored] walmart battery with 540 cranking amps thats not enough for the car.

Is this some kind of parasitic drain/ground problem known by Nissan owners?

Where to start? Any input would be helpful

 

[OVERKILL]

If you own a multimeter it is pretty easy to check for both the alternator charging and whether something is causing a draw.

 

[LeakySeals]

Originally Posted By: OVERKILL
If you own a multimeter it is pretty easy to check for both the alternator charging and whether something is causing a draw.


I do. Was planning to test at the battery terminals. Check voltage engine off, then running. Should I test another way?

 

[Ducked]

Originally Posted By: LeakySeals


Is disconnecting battery while running an accurate alternator test in a fairly modern car?



I think its supposed to be a pretty accurate way of breaking it, but I dunno exactly how reliable it is, not having tried it (yet).

I MIGHT get away with it, because my car is 1986 and doesn't have much electronics, but I still might fry my alternator. In a 2003 you probably have more systems vulnerable to voltage spikes.

Not the same thing, but I did accidentally try reversing polarity on my motorcycle a while ago but havn't really fully confronted the consequences yet, though its definitely broken.

I doubt its the battery, but I believe they'll test them for free, or if you've got another vehicle you could swap one in.

 

[mk378]

Battery voltage while running should be more than 13.5 volts. Measure on the tops of the lead posts that are part of the battery, not the terminals that are part of the car.

Never disconnect the battery while the car is running. Disconnecting the battery while the car is parked is a good test to see if it runs down by itself or something in the car is draining it.

Ideally, charge the battery for at least a whole day with an AC powered charger before testing it.

Does the "battery" light on the dash come on when the key is on engine not running and go off after starting? That light is controlled by the alternator.

 

[Olas]

What does the IND light tell you?

 

[Ducked]

Maybe work through this:-

http://www.aa1car.com/library/charging_checks.htm

 

[HerrStig]

Disconnect one battery cable with engine off and measure the "parasitic" draw of the computers in the car, by putting an amp meter in series with the cable. Some computers draw more current as they age. To test the alternator the engine must be running, a DYI test is to get the car started and measure the voltage at the + terminal with everything in the car "on". You ought to see 14 +-volts with the engine turning at 2000 rpm .
If not that high the alternator (perhaps because of worn brushes) is not charging properly. A Denso alternator, OEM on a lot of Japanese care, ought to go close to 200,000 miles on the OEM brush set. Before throwing a lot of parts at the problem be sure to check all the grounds including the battery to body ground wire and the alternator to engine block to body ground conductors. if the car has an alarm system, pull the fuse. BTW, I have almost three years on a Walmart 49 dollar battery.

 

[Dave Sherman]

Disconnecting the battery with the engine running is usually a very bad idea. Older alternators could put out high voltages and cause damage if the battery wasn't there to stabilize them. Does your charging indicator (battery light) light up with the key on and the engine not running? Can't speak for a 2003 Nissan, but the charging light was sometimes a necessary item to provide some battery voltage to the regulator circuit in order for it to start regulating. No light? Regulator circuit is questionable, and if the bulb burned out the alternator might not be working.

 

[ARCOgraphite]

Look at the wires to and fro the ALT. also make sure all GNDS are connected. An engine swap is almost a GUARANTEE GND wires are left off - and there are TONS of them on a NISSAN wiring nightmare. Start with chassis/body to engine then batt to engine, then batt to body.

 

[Chris142]

Many newer cars will not run without a 12 volt referance so disconnecting the battery with it running is not a valid test.. this old school thinking needs to go back to 1955 as it has no merit today

 

[javacontour]

Originally Posted By: ARCOgraphite
Look at the wires to and fro the ALT. also make sure all GNDS are connected. An engine swap is almost a GUARANTEE GND wires are left off - and there are TONS of them on a NISSAN wiring nightmare. Start with chassis/body to engine then batt to engine, then batt to body.


This!

Make sure you have good grounds between engine, body and battery. That can fix a multitude of problems. Since the engine was swapped, it is possible a ground was missed during re-installation.

 

[MaximaGuy]

Originally Posted By: LeakySeals


The alternator is buried underneath engine so its not an easy swap.



The alternator job is on relatively easy and 2 long bolts and it is out. Check GNDs before swapping the alternator

 

[Gasbuggy]

Those things are quick! 03 had the 3.5L

 

[RooflessVW]

Charging issues are simple, and close enough to being the same on every car.

Check voltage across tbe battery with the car off. Should read 12.6v, 2.1v for each cell.

With the car running, it should be 13.5v+

With the car running and EVERY ELECTRICAL ACCESSORY turned on (wipers, lights, fans, etc) the voltage should not drop.

If it fails the first step, charge the battery. If it still fails the first step, replace (and charge!) the battery.

If it fails either of the other two steps, start looking at replacing the alternator.

As mentioned above: check, clean, or replace ALL grounds. With an engine swap done by an unknown there are likely some broken/missing/loose.

 

[The_Jeff]

Originally Posted By: ARCOgraphite
Look at the wires to and fro the ALT. also make sure all GNDS are connected. An engine swap is almost a GUARANTEE GND wires are left off - and there are TONS of them on a NISSAN wiring nightmare. Start with chassis/body to engine then batt to engine, then batt to body.


Well it did run 40k on the new used motor.

I suspect the computer/ BCM runs the alternator on these things.

 

[LeakySeals]

Battery has been charging for a total of 2 days on the Battery Tender Junior. One with the battery terminals connected, one with the Neg terminal disconnected. The Junior's status lights never change to a flashing green (80%) or solid green (fully charged). Just solid red (charging). Perhaps the Battery Tender Junior is not enough to charge a car battery. Works well on a tractor battery so I know there's nothing wrong with the tender.

I disconnected the tender and tested the battery disconnected from the car. 12.2v
Connected to the car 12.0v
Started the car tested at terminals 11.25v - the voltage goes down!

 

[OVERKILL]

Sounds like your alternator is indeed pooched.

 

[meep]

yes. something in your charging system is not working. all troubleshooting items above should be considered.

1. are ALL wires connected?
2. is the alternator well grounded?
3. is the alternator receiving field coil activation from the ECU? (assuming external regulator)

If you do not understand questions 1-3, you need to do some google-foo to understand what you are looking at, find a local knowledgeable friend, or be willing to spend a little $ for repair.

A battery tender can charge a flattened car battery, but it can take it a couple days and may also cause it to thermal on/off, adding to the time needed.

-m

 

[mk378]

Remove alternator and bench test it.

That the battery was able to start the car is a good sign for it, but clearly more charging is needed. As others said, battery tenders are not intended to recharge a completely flat battery, but it will eventually.