vball_max

iTrader: (5)

I made it! No changing the battery in the rain for me

No.....there wasnt any warning at all.....when both lights came on this morning, it was the first indication that there was a problem.

I ended up driving ~25 miles after they came on with no lights, no radio, only used the defrost and wipers when absolutely necessary, and used the brakes as little as possible. When we tested it after, the alternator wasnt charging the battery. Considering my battery was the original battery (8 years old) I am really surprised I got that far.

I got a new alternator from advance auto (used promo code "BIG40") and got $40 off, so it was only ~$120. And a new die hard gold battery

vball_max

iTrader: (5)

My brake and battery lights came on again this morning!!!

I have a new alternator and a new battery, so what could the problem be now?

Do you think I could have gotten a bad alternator from the store?

Please help!

Nelsito65

That's always a possibility. What was the voltage output of the newly installed alternator?

BlackMacks

iTrader: (3)

While it's possible (and some say borderline likely) that your new alternator is bad, I'm gonna say double check the install. Make sure the signal plug is clean and seated correctly, make sure the power wire is free of corrosion. I cleaned all the grounds in my engine bay before replacing my alternator, tho that wasn't the problem, it was fairly easy and quick to do. Make sure your battery terminal bolts are tight, etc.

What you need to do is plug a fluke or volt meter into your cig lighter and get an idea for your system voltage, that'll give you an idea what's really going on. I just don't trust that battery light, mine never came on when my old alternator crapped out.....

vball_max

iTrader: (5)

When the new alternator was installed, my mechanic tested it and it appeared to be doing fine. He didnt say what the voltage was, just that it was charging.

When I bring it back to my mechanic, i will have him double check the connections, grounds, etc. to see if it could be anything else before he replaces the alternator again.

The thing that I find odd is that i drove it ~50 miles with the new alternator before the light came on, and it was fine up to that point..... does that point to anything specific?

Thanks for the help guys.

Max_5gen

iTrader: (2)

I had such experience - one of the brushes was broken and it lasted for slightly more than a week. You need to get voltage reading to be sure.

yudkib

hate to bump an older thread, but im running into this issue as well.
brake/batt lights come on when the car is started dead cold, and go away when its at operating temperature. if its warm they wont come on in the first place.

the alternator and battery were replaced when i picked up the car, and the dealer just changed the harness. still no dice. they tested the alternator and said it was working fine (i didnt get an exact number). i would be more worried, but its dead consistent, and i know the stuff is new. ive had no problems starting or driving over the ~2000 miles ive had it.

suggestions? bad voltage regulator? bad ground?
voltage at terminals is 12.65 when car is off, 14.6 when running at idle with light off.

Max_5gen

iTrader: (2)

What voltage do you see on cold engine with lights on at 1k rpm?

yudkib

not sure, you have to wait like 8 hours after the engine was running for it to be cold enough. ill take a look now, actually... should be about time...

Max_5gen

iTrader: (2)

My point actually was to measure it when the problem is present. You said it happens on cold engine so that's why I asked to measure it at that time.

yudkib

i hear you, i just didnt want to wait until tomorrow morning to post haha.

car still isnt cold enough for the light to come back on, even though i havent driven it in almost 6 hours...

Max_5gen

iTrader: (2)

That's why you don't have charging related problems yet - it seems engine manages to warm up faster than battery get discharged and then everything gets back to normal as you confirmed by measuring voltage.

What was the reason to replace the alt. in the first place?

yudkib

when i went to test drive it (again just 2-3 weeks ago), it started fine twice, and didnt start when we went to pull it in the bay. they said it was the first time it happened to them, and based on the relationship ive got with them now, i tend to believe them. they said it would be fixed before i picked it up.

they swapped the battery since it was ancient, the alternator was putting out low voltage so they changed that too. the alternator and battery are clearly BFN, and i took the car to them once to see if they could figure out what was going on. they tested the alternator there to make sure it wasnt a DOA unit and said it was fine. thats when they changed the harness with no effect. thats where im at now...

Max_5gen

iTrader: (2)

I see, makes sense. The only problem with this story is the alt could be warmed up from the previous drive so it naturally didn't show any problem. I wonder if they were performing the check while the batt/brake lights were lit.

yudkib

well, i tried this twice. took the car out for a short drive last night, lights were on, RPM was at about 1100, voltage was 11.75. when i arrived at my destination voltage was 12.65 at idle (light off), then 10 mins later it was the same with the engine off.
i figured i might have misread the voltmeter since it was dark, so tried again this morning.
voltage was 12.55 before starting, started it (lights were on) then revved it for a min or so to get it warmed up, and voltage was 11.77 at 1100 again.

bad alternator? case open and closed?
(edit: i should mention, all voltages were taken from the battery terminals, not the alt itself)

Max_5gen

iTrader: (2)

Yep, it's bad alternator, but not necessarily voltage regulator. Bring this to the dealer's attention and they should fix it as you were charged for alt replacement fairly recently.

Battery posts is the correct place to measure voltage, that's what voltage regulator is supposed to 'sense', it has separate wire for this.

yudkib

excellent. thanks for all the advice - im sure the parts are still under warranty. it should be going in tomorrow night, fixed thurs, and ill know if it worked friday. haha

deathmagic

i had the same problem just a few days ago. I just added some water to my battery, and it started running bak up. Maybe u can try that?

flyinon2

I have now had the same problem for the past few weeks on my 01 Maxima. I replaced the alternator and battery this summer and everything was fine until the weather started cooling off. First I heard a short "squeal" when the car was started cold. I figured that it was a loose belt because I had replaced it when I replaced the alternator. I tightened it and it seemed to help for a few days but then I started getting the battery and brake light which would stay on for a few seconds, again, only after the car had been sitting for a few hours in cold weather. The past few days, it has been a lot colder at night and the lights still come on but they stay on for a little bit longer now when it is cold. They were probably on for a mile or more this morning. They still don't come on when the car is warm or for that matter when the air temp is warm. I checked the voltage a couple of weeks ago and it was around 13.8 - 14.0 at idle but it was warmer then and the lights were not on. I am going to try and get the voltage with the lights on to see what it is. I have still heard the squeal once or twice since I tightened the belt so I am not sure if it could possibly be the belt or the alternator. Any ideas?

flyinon2

I checked the voltage at the battery this morning after I started the car cold with the battery and brake light on and it was only 11.5. I waited about 5 min. for the car to warm up a little and for the lights to go out and checked it again. This time it was 14.5 volts. Why would the alternator not work when cold but work fine after that, just a bad brush or something?

yudkib

dunno, but that ended up being my issue...

brought the car in last thursday to get fixed, problem is solved. DOA alternator.
it seems like a lot of people who are having this problem have replaced their alternator already - and if its warm out, its not an easy thing to catch early. im thinking its just bad quality control from the manufacturer - and maybe OEM is the best way to go.
from what ive noticed online, ordering the OEM hitachi unit is basically the same price (or possibly slightly cheaper) than going into autozone and buying a duralast one. just make sure you look up the correct part number, as they changed at weird intervals between the 5th and 5.5gen.
also, there are also much better companies making replacement alternators than anything you can find at napa or advance... ive seen denso and bosch replacements and im sure theyre better than duralast.

le224

Alright I have the almost the same problem on my 4th gen maxima. When I'm driving my hid turn off then I noticed my radio shuts off and I look at the dashboard and I notice the battery light and the brake light are both blinking. About a year ago my friend told me its a trouble code but I don't want to go changing parts and waste my money. I heard alternator but I'm trying to make sure what it is. All response will be thankfull

Ghost_54

iTrader: (13)

I'll put my money on your alternator is heading south for the rest of its life, you have classic symptom of an alternator no longer delivering the correct voltage to the battery and engine systems. Have the out put voltage checked I know when mine displayed the symptoms it was only putting out 6 volts which is barely enough to crank over the engine with all the accessories turned off.

cali818

I have same problem but my car turn of and the battery was dead but when I connect a new battery and I remove the ground cable the car turn off any idea?

cornholio

iTrader: (1)

replace your alternator?