# Going on 4th or 5th alternator...enough is enough



## jamesd3rd (Jun 10, 2004)

Ok there's got to be something else going on here. I have a '93 Altima that I bought used in '96. The car has been pretty reliable with one exception. I am constantly replacing the alternator. Over the past 8 years I've had to replace the alternator about 4 times. Now after replacing the thing in November of last year, it looks as if I'm replacing it again. I had the battery replaced last August. The car ran fine until November. While I was driving home from work I noticed all the panel lights going dim and the car eventually died. A mechanic checked the alternator and determined the output was not up to spec. So I had it replaced. So it ran fine until a couple days ago when it would not start. I charged the battery and it ran ok but I watched the clock as I drove yesterday to see if it would go dim after a while. Sure enough after a couple hours of driving the car failed and would not start.

I bought the car in June of '96. The first time the alternator was replaced was around fall of '97 the again a couple months later. Then again in July of '98, November of '03 and now. There may have been a replacement between July '98 and Nov '03 but I can't recall.

I can't believe that an alternator would just fail that frequently. During that time I think I've replaced the battery about 2 or 3 times also.

Could there be something alse going on in the electrical system that's contributing to so many battery and alternator replacements??


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## KA24Tech (Feb 2, 2004)

Hey James,
Have it tested to see how much of a current draw is there when the car is off and when it is running. An easy way to see is when the car is off remove the negative battery cable, wait a minute and then hook it back up if a decent spark occurs then something(s) is/are drawing too much. Also try to determine if there is a short or partial short to ground in the main harness although this will show up in the current draw test as well. Test the harness from the alternator to ensure that it is not in a constant full field condition.
I hope you are getting an alternator with a lifetime warranty but it sounds as though the alternators are working themselves to death. Also I have seen many of these "lifetime warranty" parts which are needing annual replacement because the electronics inside are so cheap.
You should also have the battery tested because they can cause new alternators to go bad in a sort of leap frog effect. It happens when they are overcharged constantly by an alternator and then drained heavily, a deep-cycle type of loading. 

Troy


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## jamesd3rd (Jun 10, 2004)

Define 'decent spark' when reconnecting the negative terminal.

If there is a short somewhere in the harness how would I isolate its location. Those harness run all over the place and are so stiff due to all the wire bundles.

What is 'constant full field condition'?

As for the 'lifetime warranty', all the replacements were made at the shop where the car was being serviced and the best warranty they offered was something on the order of 3-6 months I think. Probably closer to 3.

I was under the impression that a rebuilt alternator had all new parts put in it. The only thing that was kept from the old unit was the housing. I've been told that a lot rebuilders just replace the 'bad' part and everything else remains with all the wear and tear it had. This to me would result in a VERY unreliable unit. How can I make sure I'm getting a reliable product. I'm just wasting my money replacing the same things over and over again.

My wife's '93 Excort is more reliable. That thing refuses to die. And it's beat to hell. The Nissan alternators I've been getting are worthless.


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## KA24Tech (Feb 2, 2004)

jamesd3rd said:


> Define 'decent spark' when reconnecting the negative terminal.


Of course a sizeable spark as if the lights were on or the ignition key was on. Just try to have all of the doors closed or any controllable draw on the battery when you do try it. 



> If there is a short somewhere in the harness how would I isolate its location. Those harness run all over the place and are so stiff due to all the wire bundles.


You can take it to a shop to see how much current is being drawn at idle once again you would turn off all of the accessories but just have the engine running as well as shut off. When it is shut off it shouldn't have more than a couple hundred milliamps. The other way is to take an ohmmeter and connect the negative to the ground cable with the battery disconnected on both cables and thenwork your way thru at different point starting at the positive terminal on the battery and then to the alternator and into the fuse boxes under the hood. Also check the resistance between the engine and chassis, battery to alternator, battery to chassis, battery to engine, and alternator to engine. Check on both the positive and ground sides individually.



> What is 'constant full field condition'?


A full field condition is where the alternator has full battery voltage applied to the stator (the wire wrapped around and around inside the alternator) causing the windings to produce maximum magnetic field which transfers to rotor which spins around passing thru this magnetic field inducing the charge which produces the electric current. This electric current is an AC waveform so a part called the rectifier bridge changes it to the DC which the vehicle uses. The full field condition induces the alternator into producing maximum output without any regulation. Symtoms of this are high output voltages above 14.5v, a very hot alternator case shortly after starting the engine, and excessive battery corrosion from the electrolyte boiling. 



> As for the 'lifetime warranty', all the replacements were made at the shop where the car was being serviced and the best warranty they offered was something on the order of 3-6 months I think. Probably closer to 3.


I would consider a rebuilt from one of the parts stores which carry a lifetime warranty. I believe a good shop should have at least a year warranty on one.
The thing about a lifetime part is you can take off the old part and exchange it without any extra expense other than time as long as you own the car. 



> I was under the impression that a rebuilt alternator had all new parts put in it. The only thing that was kept from the old unit was the housing. I've been told that a lot rebuilders just replace the 'bad' part and everything else remains with all the wear and tear it had. This to me would result in a VERY unreliable unit. How can I make sure I'm getting a reliable product. I'm just wasting my money replacing the same things over and over again.


Your definition of rebuilt is actually called a remanufactured component. This is why most dealer parts are more expensive than most aftermarket because they remanufacture things like an alternator or an automatic transmission as opposed to just rebuilding it which is just replacing the bad or worn components. Also most aftermarket rebuilders use cheap electronic components in the process.
I would see if you can get an alternator on you own which has a lifetime warranty or one that is remanufactured from Nissan or quality parts stores. I also think that you should find a new shop to do the repairs that has a better reputation since it seems that they aren't doing much more than taking your money without really fixing the problem only patching the problem.



> My wife's '93 Excort is more reliable. That thing refuses to die. And it's beat to hell. The Nissan alternators I've been getting are worthless.


It isn't Nissan alternators that are the problem it is the rebuilder/repair shop that is to blame. I rebuild my own alternators with genuine Nissan parts (which my Nissan dealer thinks that I'm crazy) but I inspect and test all the components myself and have yet to have any problems with long reliable service.
On your wife's Escort, just make sure that you change the T-belt on time as they have a tendancy to break not too long after they are due.

Troy


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## jamesd3rd (Jun 10, 2004)

This one will make you laugh. I just got the car out of the shop a couple hours ago. I stopped off at an Autozone and bought an Optima Redtop battery. I installed it while in the parking lot. About 5-10 minutes down the road the brake AND battery light came on. Every post I've read says this is an indicator that the alternator is going bad. What the *@)!)! is going here??? I just got the thing out of the shop!!! Don't these idiot rebuilders test their product?? It's no wonder jobs are being shipped overseas with the crap that gets turned out here. What should I expect to pay for a remanufactured alternator as opposed to a rebuilt? The rebuilt was about $185 plus labor.

I did replace an alternator the first time it failed but the bracket was a bitch to line up. I think it took over 2 hours to get the thing in because it was so hard to line up the holes. To say nothing of the fact that I can only turn the nuts about 5 degrees at a time when tightening it.


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## Cuban_B_93_XE (Apr 24, 2003)

My alternator on my sentra went but thats after a 1000w amp and other toys.


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## zlr101 (Nov 17, 2003)

I work at autozone i would never buy the a rebuilt alternator maybe a duralast but i would go knew avg life of a cheap on i would say about a 1yr maybe 2 but i think there might be other problems like was stated earlier.


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## 95Alty (Sep 3, 2007)

I know this is an old thread, but here is my input, since I just had this problem:

I agree about using a genuine Nissan alternator (rebuilt). Nissan replaces everything inside, but the housing is original. I thought I was saving $$ by buying a "Champion" brand alternator from Canadian Tire. My original lasted almost 12 yrs. The Canadian Tire brand lasted 13 months. The next replacement from them was noisy. I got a refund on the "Champion" brand and installed an original Nissan alternator...so far so good. If this original part dies, then something is shorting it out and the electrical system will have to be tested.


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## smj999smj (Jan 1, 2006)

I had a friend who put 5 Pep Boys brand lifetime warranty alternators on a 85 Stanza (this was a long time ago) within 4 weeks until he finally wised up and installed a genuine Nissan reman. like I told him to. After that, no more problems.

About the only aftermarket alternator I have any faith in is the Cardone "Select" alternators which are all brand new and come with the testing results for the alternator on the box. Still, if it were my Nissan, I would get a genuine Nissan reman. The same goes for starters and most other replacement parts.


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## rbo1577186 (Jan 16, 2005)

X2 on the Nissan Factory Alternators. They are GOOD PRODUCTS!! If you plan to keep your Nissan a while, it's the only way to go - period. They aren't cheap though...

Don't buy alternators from Advance/AZ. You can pull a dozen off the shelf and 4 of them (new in box) will be bad. Get them from a higher end Auto Parts Supplier and check to be sure they don't use the same brand as Advance/AZ.

If it hasn't been mentioned, has the cable connections been checked, and if applicable has the voltage regulator been ruled out?

One more note on the topic, when replacing an alternator, be sure to recharge the battery before using it. Letting the alternator recharge a low battery can overwork it and cause it to fail prematurely, overheat, and possibly catch on fire.


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## smj999smj (Jan 1, 2006)

Voltage regulator is internal of the alternator...

There's a reason why Advance Auto Parts can have a string of bad alternators and why they can sell them so cheap. I once met a guy that worked where they make AC Delco alternators, which Advance Auto sells among other stores and GM dealers. He said when they come across an alternator that fails during testing, they take the 100 alternators assembled previous to that one and the 100 alternators made after and sell them to stores like Advanced at a discounted price. This helps prevent a run of "bad" alternators from ending up at the GM dealers.


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## rbo1577186 (Jan 16, 2005)

I didn't know, some are external, some are internal.


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## smj999smj (Jan 1, 2006)

Most alternators made in the last 25 years are internal.


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