# Is this a bad alternator?



## mricke (May 25, 2006)

Any help would be appreciated.

1993 Maxima. I've done a bit of research and think I know what the problem is, but any suggestions would be very helpful.

In the past 100 miles, the battery light came on and the brake light came on. It's idling pretty roughly around 400 rpms. It hasn't stalled, but it feels like it's going to.

From what I've been able to figure out it's probably a bad alternator (something about the ABS detecting low voltage sets off the brake light), but it's otherwise not suffering from any alternator-related symptoms (like dim lights at idle). I also noticed that my battery connections were pretty cruddy (the car is at a cousin's for the week so I haven't had a chance to clean them off). Is there any possibility that dirty battery terminals would affect voltage that much? 

Any ideas or confirmation?

Thanks.


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## MyGreenMax94 (Dec 17, 2005)

Yup...The battery/brake light combo is a classic maxima alty problem...

The cruddy battery connections would more than likely give you a no start condition...Not set warning lights off..


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## mricke (May 25, 2006)

Thanks for the reply. I plan on replacing the alternator after I double check the belts and test the battery. Any thoughts on changing the alternator would be much appreciated as well. It's a VE30DE, and I'm a little nervous about doing it myself due to space issues along the right side of the engine.


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## MyGreenMax94 (Dec 17, 2005)

mricke said:


> Thanks for the reply. I plan on replacing the alternator after I double check the belts and test the battery. Any thoughts on changing the alternator would be much appreciated as well. It's a VE30DE, and I'm a little nervous about doing it myself due to space issues along the right side of the engine.



Just use the autozone repair link...

http://www1.autozone.com/servlet/UiBroker?UseCase=RG001&UserAction=viewRepairGuideYMMEYear

Click 1994 year. 

Click NISSAN/DATSUN

Click MAXIMA 

Click Engine electrical

Click Charging system

Click Alternator

Then follow the instructions...


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## mricke (May 25, 2006)

Hi everyone.

When I checked the old alternator, it was putting out a lower than normal charge, so I went ahead a replaced it. Now I'm around 14.5 volts. However, the battery light and the brake light are still on. 

Additionally, it is still idling low (4-500rpm) and running a bit rich. I adjusted the idle just because I'm more comfortable with it around 700, but it's still rich and sounds like it's missing in a non-rhythmic way (perhaps a fuel problem?). At any rate, I drove it 300 miles yesterday with no trouble at all, save the dummy lights and the funky idle. 

So i know it's not the alternator. This spring I put on a new fuel filter, air cleaner, and replaced 2 fuel injectors. I inspected closely for a disconnected hose or something and found a small one disconnected, which I reconnected, but it didn't fix the idle. 

Any thoughts? vacuum leak, dying fuel pump, egr valve?

thanks


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## internetautomart (Mar 8, 2004)

it could still be the alternator.
you may have a bad Voltage regulator in the new one.


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## mayfew (Aug 18, 2004)

Where is the voltage regulator located and is there any way I can test it?
Any know if nissan wiring is know to go "bad" between alternator and battery?


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## Matt93SE (Sep 17, 2003)

the regulator is internal to the alternator. It's a standard Bosch replacement part, IIRC, but you've got to be able to crack it open and do it yourself if you want to replace it.


As for what goes bad, the cable between the battery and alternator is definitely a wear item. neither of my 93s ever had a problem with the large cable, but the small coil/sensor wire that controls the thing charging was damaged in a wreck before I got the car. i had to cut the entire front end harness apart to find the issue. royal pain, but I eventually found it and spliced it back together.


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## mayfew (Aug 18, 2004)

I just got a new battery after i was unable to stat the car after class. I used jumper cables to start the car and the engine ran fine all the way home without a battery light. at home the car still would not start. but now with the new battery in my car the new battery light stays on but the car starts fine. I have not had the battery&brake light problem yet, so I do not know if my problem is the alternator. there was no problems in the morning with starting the car or battery lights. what the deal? I am charging the new battery, just in case it lost charge while on the shelf at the store.


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## Matt93SE (Sep 17, 2003)

take the car to a parts store where they can usually check the alternator and battery out while the car is running.

I'm going to bet its a bad alternator as well.


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## mayfew (Aug 18, 2004)

Ok after a new battery and a new alternator, the battery, ABS, brake light came on. car starts and runs fine whats the deal?


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## mayfew (Aug 18, 2004)

the lights did not come on at first, only after 2k rpms. 5 min of driving later the lights started to stay on all the time.


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## mayfew (Aug 18, 2004)

Bad regulator in the new alternator ??


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## mayfew (Aug 18, 2004)

Battery still not charging. I have to use external battery charger. 18+ volts from alty at studs, full continuity from positive stud on alty to positive on battery, same with negative studs. no bad fusible links. whats the deal? might have to take it to my mechanic.


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## mayfew (Aug 18, 2004)

ok it was the alternator. I changed it out for a different one and no problems now. My only problem is that the parts store kept trying to give me bad altys(or cores), three in a row, they were rusted.


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## buzzdav (Aug 9, 2007)

New alternator is expensive. I would suggest new brushes and diode for the old one! Simple easy job! davbuzz


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