scottatl

So I replaced the alternator with a Hitachi reman. Now the brake and battery light are on.

Note, the battery reads 12.6V when car is off
When engine is running battery reads 15V

I cannot see anything wrong with the alternator harness, but not sure how to check that.

Any other ideas.....

2000 Maxima SE, 80k miles

DennisMik

iTrader: (2)

To start with, lots of people have problems with rebuilt alternators. You may have just joined the group.

Re you certain the small plug on the alternator is plugged in? Plugged in all the way? That the contacts aren't pushing out of the plastic connector?

I'm a little confused, though. Are you saying that the brake and battery lights are on, yet you have 15 volts when the engine is running?

One thing for certain - that alternator is no good. You should never have 15 volts. Spec is 14.1 to 14.7.

scottatl

when you stay the small plug, you are talking about the black one right. there are only 2 connections. the one to the main battery which is a eyehook and the one black one.

I am going to go read the volts again...

scottatl

yep, so it high voltage the sign of a bad alternator?

boondoxmax

iTrader: (1)

I learned my lesson with reman alternators. I had a bad one right out the box. Got a brand new unit and no problems..

chrome91

iTrader: (1)

most reman VQ35 alternators fail quickly. any Napa reman alternator we put in a Maxima, Murano, Altima, etc at work comes back wtihin 4-6 months not charging. or its bad out of the box like yours

CMax03

iTrader: (3)

I think most problem reoccur due to the way most people pull on their harness to disconnect the plug from the altenator. It's a harness issue otherwords...and once they install the new altenator there's still an issue...I've installed a reman altenator and thought the readings were a built low...So I double checked it with my calibrated VOM that I use @ work and the Voltage was fine...My home VOM was reading a bit low...but now I run a battery analyzer with the car running and not running to measure the actual CCA and actual battery output....So it could be an inaccurate VOM that's throwing your readings off as well.

vqmaxman

The alternator is gonna crap out the Battery. The negitive charge is gonna give the battery a negitive charge. The battery is gonna develop a negitive cell than just die. Check the harness if its bad or loose than go to the alternator I am sure the vol meter is reading right and the alternator is bad.

scottatl

How could a bad harness increase the voltage on the alternator? The harness does look beat up, so if there is a chance it is the harness I will go pick a new one up.

george__

iTrader: (1)

Another pOS alternator bites the dust thread

world conspiracy

Child_uv_KoRn

iTrader: (7)

Assuming that is correct V, then it's definitely too high.

Not to be a ****, but that does look like a very cheap voltmeter.
I would check it with a better one to be sure, but I would guess it's just too far out of spec.

scottatl

Actually cheap is being generous. Got this unit from Harbor Freight for free with one of there million free coupons. But I checked a few items and it was spot on for those. Guess I will check another one of my car alternators.


still, can a harness make volts increase??

Child_uv_KoRn

iTrader: (7)

I don't know how lol. I was just thinking that maybe the meter was reading high instead, but either way would set the light on. It would just be nice to know for sure if it's in spec or not.

Donkeypunch

When your car started dieing did the abs light come on and then the seatbelt?

maxiiiboy

I also feel the problem is in your harness, or perhaps in the connection between the harness and the combination meter. This is why: a) You have ~15V (never mind the exact number) on the battery, so the alternator is charging; b) If your battery light is on, then the voltage is not getting to terminal #68 of the combination meter (see FSM, EL-124).

Once you fix the harness, the brake and battery lights should be off. You should then verify, with a good meter, that the charging voltage is in 14.1-14.7 V range.

Donkeypunch

Where's do you find the cheapest one?

That price about right? Dealer would be like +$400 I bet.




Here's a bosch.

vqmaxman

In most cases sometimes the looses or bad connection or bad harness can cause the ecu to spit out extra voltage to get the charge it's looking for, I seen this happened untill the fuse or the circuit blows.

maxiiiboy

Can you explain how would the ECU manage to "spit out" extra voltage?

george__

iTrader: (1)

Maybe the AUTO motor mounts are dying and giving out electrical woes

DennisMik

iTrader: (2)

WHAT!?!?!?!? How do you come up with this stuff?

scottatl

I ordered a harness, I hope I have it by the weekend. I agree it seems odd that a harness issue would increase voltage, but for 22 bucks I will give it a try before I take out the alternator, send it back, get a new one, put in the new one, send in the core and then cross my fingers that it was a bad alternator.

I will tell you that this car is easier to work on than my Jag XK8 which has an endless number of mysteries that need to be solved.

george__

iTrader: (1)

If AT motor mounts can fry a ECU, who knows

vqmaxman

If you ever tried playing with the harness neg or pos unplug while the cars running the car while rev and give out on some cases the ecu will spike up or downwards and give out, it also depends on alternator and battery health. How ever you look at it's a bad idea.

Donkeypunch

There should be a light that comes on when it's putting out less then 13v or so so you know your alt is pwned.

They just let you run that shiiiiit dry and leave you stranded somewhere. Dumb acc nissan.

My oem alternator just quit on me that's why I'm alittle miffed.

The reman is less half the price of the dealer one with lifetime so I'll just try out a reman.
Dealer price was like $380 I think.

vqmaxman

I used the oem replica aka the tough one from advanced auto parts that was the best and great alternator, I had that in there in my white 99 sel before my sister totalled it. The power the charge was just great that car ran like it was on juice.

MichMaxFan

Just take your existing one to a good electrical shop and get it rebuilt locally. When I started thinking about all the rebuilt starters and alternators I started wondering why mine couldn't just be rebuilt rather than getting one that may have not been done very well. I'm happy with getting mine rebuilt. Just a thought for you.

scottatl

Arghhhh,

I put in another alternator (new, not rebuilt) and a new harness. The brake and battery light are still on.

Any other thoughts...........

maxiiiboy

Well, what's the voltage on the battery, with the engine running?

klobbersaurus

the alternator is overcharging for sure, there should be a wire in that harness that lets the alternator know the battery voltage, if it cant sense that voltage, then it will keep upping the voltage, you might have an issue with that wire,

what your gonna have to do is check the resistance between that signal wire and the battery, if it is open, then you have a broken wire somewhere in the harness

george__

iTrader: (1)

you got crap alternator

scottatl

i cant believe i got 2 bad alternators. The first one was a re-manufactured Hitachi and the second was a new one from a pep boys.

if I really did get 2 bad ones, i will never again go to veges.

Daniel VQ30life

iTrader: (2)

do yourself a favor and never buy parts for your maxima at pep boys again

rebelhell

iTrader: (1)

I've had mostly good luck with remans and new alternators from Autozone/Advance/O'Reilly. Secret is to make them take it out of the box and bench test it before you even pay for it. The failure rate is just ridiculously high for these things. This isn't a 100% guarantee that it'll be good, I've seen bad ones pass before, but it certainly improves the odds a bit.

scottatl

Well I dropped off the car at pep boys for them to figure it out. I guess it is possible that i got 2 rotten apples from two different barrels. I dont usually go there for work, but if the alternator is bad they are going to have a hell of a time collecting from me for the shop time.

Pep Boys and AutoZone get the parts from the same factories and paste their own labels on them, I really doubt there's any difference.

I am not keeping the car that much longer, it has served me well for almost 16 years, but I have my sights set on the new generation. I was going to give it to my son who is learning to drive, but the safety features on the new cars are just so much better.

scottatl

Well I just put in my third alternator, and I had the store bench test it before I put it in. I also have a new harness.

I tried an extra ground on the alternator to see if that was the issue and it was not.

I trickle charged the battery to make sure it was full.


Any other ideas???

maxiiiboy

You keep asking for help, yet you have not responded to the two constructive suggestions you got (posts #28 and #29). That's annoying to those trying to help you; a bit reluctantly, I will help you one more time.

First, you have not told us what your problem is. Are the battery&brake lights still on? If so, is this the only problem you are having? (below, I assume the answer to both questions is YES).

Your problem should be easy to diagnose - provided you follow these instructions to the letter:

1. Get (buy, borrow, or rent) yourself a decent meter. I suggest buying - expect to spend $40-50. Do not use that crap from HFT.
2. Verify Charging Voltage OK. Start the car, and measure the voltage on the battery. It should be in the (14.1-14.7) Volt range. If above, the regulator (component of the alternator) and/or the harness are suspect. Read post #29 by Klobbersaurus again and act accordingly. If below the range, then either: a) The alternator does not generate enough voltage, or b) The alternator generates enough voltage but the voltage drops because of poor wiring/connectors/etc. between the alternator and the battery. (Remedies should be obvious; if not, ask). In either case, do not move on until your charging voltage is the (14.1-14.7)V range, even with your lights an AC on.
3. Verify Battery and Parasitic Drain. A good battery should hold a voltage of 12.5V (plus/minus a fraction) "indefinitely". A good alternator should not drain any current from the battery when the car is shut off. To verify, shut off the car and wait 20-30 minutes, long enough for the ECU to go asleep. If your meter supports inductive loop Amp measurements, measure battery drain current: it should be only ~ 200 mA or so. If not (no inductive loop for Amp), measure battery voltage in the evening and the next morning. If there is a measurable drop, then: a) Your battery is bad, and/or b) The alternator or other device is draining your battery. Move to #4 below only when you are satisfied that the battery is OK, and that there is no parasitic drain.
4. Bad Cluster Lights/Controls? If you get to this point, then both your alternator and your battery are functioning well. If your battery and brake lights are still on, then the cluster itself and the associated controls and wiring are suspect; read my post#15 above and act accordingly.

Donkeypunch

What brand was it? Did it say nissan on the cover?

scottatl

To conclude this thread

I got 3 bad alternators in a row.......

Cheap meter was spot on

george__

iTrader: (1)

Not bad... I got 5 bad in a row

Child_uv_KoRn

iTrader: (7)

So much for QC.