I have a question about my car(2002 Nissan Maxima SE) or alternator(aftermarket HO 160Amp). I have a permanent volt meter inside my car monitoring my electric status due to my audio install, I've noticed that when I'm on the highway at high speed or when at high idle, normally above 2,000 rpm, the voltage drops, below 12.6v and the battery and brake lights start to blink on and off on the dashboard, even with my radio and complete system off. What is happening?

Thank you.

 

When the battery and brake lights come on, that means that the alternator is not charging.

There isn't a lot that you can do for an alternator that doesn't charge. Check that the belt is good and tight and not glazed and slipping. Check that the thick wire on the alternator is secure and tight and check that the connector with the 2 wires is plugged in all the way.

 

with the car idling, put a voltmeter on batter positive and battery negative. if it reads under 13ish volts, alternator is probably on its way out. sounds like it is if youre getting 12.6 on the highway, should be 13.5-14.4

 

when my car is on idle, it reads above 13.8v, it only reads below 12.6v when i'm running at high speeds or accelerating fast.

 

maybe somethings up with the internal voltage regulator in the alternator when youre at high speeds? albeit on the highway you would think a bad voltage regulator would overcharge the system but i suppose undercharge is possible

 

And if it's the internal voltage regulator in the alternator, how can I repair/fix it?

 

The voltage regulator is a printed circuit board mounted inside the alternator, you would have to first remove the alternator and then open it up.

But the voltage regulator board is unique to a make & model of the alternator. So few people repair their own alternators that internal parts are difficult to find for even the stock alternator. And since you don't have the standard alternator, you will probably have to contact the manufacturer for this.

When you open the alternator up, be prepared for the brushes to fly out. They probably won't fly out of the alternator case, but they might. Depends on exactly how the alternator is made. And depending on how the alternator is made, the voltage regulator board may or may not require wires to be un-soldered for its removal.

While buying a new or rebuilt alternator is more expensive, it is easier. You do have to have a few extra skills to repair an alternator. While my experience makes me think that the voltage regulator is bad, I don't know how to test it to be 100% sure.

If you want to be brave and go and buy the voltage regulator and do the job yourself, go ahead. But based on your posts, I think that you'd be in over your head.

 

Easy to change you can get the regulator from WAI or Transpo you will also need to change the SRE bearing.i rebuilt them for years

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Wow, and I bought this alternator not long ago.

 

Well, what kind of warranty did it come with?

 

often dont anymore, back in the 70s and 80s it was common, but nowadays its more efficient to replace the alternator itself

 

I just checked I bought it more than a year ago.

 

So you bought it over a year ago. What kind of warranty did it come with?

 

Check/replace grounds before doing anything, then likely it will be the alternator at fault.

 

What grounds? Which should I specifically check?

 

I bet u got it on ebay and the middle part is either red or green. those rebuilts are fake high outputs, and dont usually last long.

 

Green is the OE color and its a powdercoat if its paint its been rebuilt

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Oh wow, good to know but it's too late for me, but thanks anyways, and where can you recommend me to get an high output alternator?

 

only advice i have is do NOT get a rebuilt Napa alternator. i (against my will) usually end up installing rebuilt ones at work, and i would say over half of the alternators end up failing within 6 months. if you have the money get a new alternator

 

Look everyones best bet is goto a local rebuilder

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I'm on mobile, r do the ground from the battery to the chassis, and from the chassis to the transmission.
there is also a ground at the alternator area.

 

I will check, but any recommendation on where to get a good high output alternator?

 

Get an OEM used alternator with decent mileage. I got mine from an 05 murano with 50k been 1 year working perfect on my 03.

I rather trust used oem than new aftermarket. Obviously new oem is the best.

 

it really depends on the rebuilder. Mass rebuilders like cardone, world, Excel Automotive and Wai use a lot of reclaimed parts which have been run thru hot wash and glass beading which tend to weaken parts.

 

You will have nothing but problems with an HO alternator. But if you insist, shop around for a good shop that does this, and pay them to build the one you already have.

 

Ok, I understand. But, then how can I create sufficient power for my sound system, if your saying to go with the oem alternator?, remember, I have around 4,500 rms in ampilifiers.

 

Better batteries, more batteries. either way, it sounds like reliability isn't high on your list of wants, so just try to find a shop that has a good reputation, or send the alternator out to be built and tell them what you're doing with it. be prepared to pay for it.

 

Ok, thanks. Anyone here with a loud aftermarket sound system on a Maxima? Any opinions or help on what to do to maintain good voltage while loud, no warning dashboard lights and no dimming lights.

 

I thought that this is what capacitors are for, they store energy and run the system off that energy and if it falls below the capacitors energy then it'll use the cars energy so basically it wont run entirely off ur alternator something like that. They have different farad ratings for capacitors, more farads the better.

Example: http://www.sonicelectronix.com/item_...k-PCX-30F.html

Not saying this is good or to buy it just an example of what im saying, do ur research and read reviews find a good one maybe this is right for you.

 

Capacitors like that are for regular aftermarket systems, not loud systems.

 

Didn't I post the answer pretty clearly directly above this post you made?

 

This is why I bowed out of this thread.

 

Some people just dont know how things work Brudder

Cjandura

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