A couple months ago, I go out to start my car in the afternoon, just like any other day. Huge whine, battery + brake lights on. I drive the car home, no problems. I continue to drive the car for the next week with no problems, and one day, the whining is gone (mostly, there is still a quiet "moaning") and the lights are off. Not wanting to take any chances, I put in a new battery (old one wasn't putting out enough amps anyway) and install an eBay rebuilt 110 amp alty with a new accessory belt. Whining is gone and no lights.

Car drives perfectly for two months. All of a sudden, one day I'm driving along and the battery+brake lights pop up during driving. However, there's no whining of any kind coming from the alternator. I drive for about 10 minutes and the lights go out?? The problem persisted. The car seemed to have them pop up the most when I started the car frequently and go out after I drove for a while, so I figured my battery level was low. However, the battery only charged for 20 minutes and the lights were still on afterwards.

Just today, I was sitting at a friend's house waiting for him to come out, and the lights had been on for a while. They go out while I'm sitting there, and I see the RPMs fluctuate a little at the same time (raise about 100 rpm and drop about 200, then raise and settle at 700).

The car has no drivability or power output problems as far as I can see. I'll be playing music fairly loud while the lights are on, and they'll still go out after about 10-15 minutes of driving. Also, the lights will turn on at completely random times, it's not always when I start the car. I have no check engine lights. Any ideas?

 

Check your brake fluid cos its low

 

alternator
I just searched for "brake battery" and there's a ton of threads, but you'll find that it has something to do w/your alternator.
edit: nevermind, figured it out... search the thread titles for "brake battery" in the 4th gen forums.
Jae

 

lol I guess my battery fluid level is low too

Thurz, I'm perfectly aware that this has something to do with my charging system. I'm trying to diagnose why it's an intermittent issue, though.

 

higher rpms=higher output from the alternator (to a point, until the voltage regulator takes effect), sounds like the alty is on the fritz and after driving for a little bit it sees some higher rpm's (or at least off idle) enough to put out more of a charge. However, start by disconnecting the battery, cleaning the terminals and the + post on the alternator.

 

Replace your alternator, again. Some will cut off completely at certain rpm levels where you'll end up relying solely on battery power for your car. From what I've read on this site good alternator rebuilds are just as intermittent as your current issue.

 

Any update on this problem i am having a similar issue with my battery + brake light coming on randomly, i replaced my battery, alternator, drive belt, same thing persist...NEED help

(sorry to bump an old thread)

 

may be a stupid question but do the maxima alts have a remote voltage regulator or are they built into the alternators?

 

dont know that, but my alternator tested fine

 

i'll see if i can find out, a fried voltage regulator can give you all sorts of hell, if its a built in then it would have been replaced with the alt but if its remote it may be another part to try replacing.

 

andrei: go buy a voltmeter at walmart ($15, the kind you plug into your cig lighter) and watch the voltage output for a couple weeks. Note the pattern. When my battery+brake lights were on, the alty would only be putting out about 12v. When they were off, it would put out about 14-14.5v.

Strange fix for me: Our family went on vacation, so my car sat in the garage for a week. Once I got back, the lights never came on again. It's been this way for about 5 months now. The alty puts out 14.3v constant.

 

thats very strange, i am looking into a grounding kit right now hoping that fixes it cause i got my alty and batt check out and they are good

 

Yep, it's built in. P/n 23125 http://www.courtesyparts.com/betasit...1814_1820.html

I think, you are seeing just battery voltage and the alternator doesn't put any voltage. I'd buy a simple multimeter and folow the troubleshooting procedure from the FSM. it's not very complicated.

 

if the alternator did not put out any voltage i would not drive like this with the lights intermittently on/off for the last 2 weeks, also if the alternator did not put out any voltage then why would the lights not stay on all the time ?

I replaced the starter and the problem is EXACTLY the same still, so i dont see how the starter can be completely dead, its either working or its not, and i think it definitely is working especially after getting it tested

Also lately when the lights come one while i am standing, the rpm begins to rise and the lights go away - this tells me that the car (whatever the part it is that takes care of voltage regulation) sees a drop and makes the engine rpm go up thus increasing the voltage production from the alternator - i THINK...

 

Still sounds like the alternator is having trouble putting out the needed 13.5V @ idle. The lights go on whenever the system voltage goes below 12V, and if they go away when you rev-up, then you know what the problem is. I was driving like that for a month until i decided to replace my alty. What sux in your case is the fact that you just had it replaced, i'd try to exchange it.

 

If you changed the alternator and battery and got exactly the same behavior, I'd suspect some "connections" problem. Check all wires, terminals, grounding and fuses.

There's no such part. I mean, there's a "IC regulator" builtin into alternator which tries to maintain constant output voltage regardless of RPM, but if it doesn't have enought rpms, it has no means to tell ECU about it.

Yet there's a "electrical load" signal to ECU. It is activated when you turn on rear window defogger. ECU will slightly open IACV to compensate increased power consumption.

 

In electric term, regulator is a "buck" circuit, which only limit to certain voltage. There are "boost" circuits which increase voltage. But these are not used in car alternators.

 

No matter what the test of the alternator says, it is BAD, and needs to be replaced. Sorry, and wish there was something else that could be recommended, but I and my ex both owned Maximas, and they both did the exact same thing right after each other. You WILL need to replace the alternator. its not a simple job, like it is with most american cars, as its at the bottom behind the AC compressor, but you can do it yourself if you are mechanically inclined.It took me roughly 7 hours when I replaced hers, it only took two when I had to do mine a couple weeks later.

 

No it does not go away when i hit the gas, i could be on the hwy going 120 km/h and the lights can come on and go away, that truly is random i have not been able to replicate the condition for the lights to come one at will

what IS strange is that they NEVER come on when the car is solid cold, for example, i drive to work in the morning, no lights, but oncwe the engine heats up after say 10 - 15 minutes of driving the lights MAY come one or they MAY not,

Tonight i had to go somewhere else after work, and got caught in rush hour traffic, crawled on one street for about 30 minutes, nothing NO lights, stop the car at my destination, do my business 10 minutes later turn her on and boom i got lights all the way home on and off...

IS THIS A GROUNDING ISSUE ? i am about to start punching my maxima in the MTFin FACE!!!

Sorry just read this post - perhaps you have not reard my thread (i am just hacking this thread for now) these lights started coming on randomly, and i replaced my original nissan alternator with my dad now this re-built unit is doing the exact same thing making me think alternator is not the issue - just to clarify, my "!" and batt lights show up together ANY TIME and nothing i do can get rid of them or replicate the issue...

i also have a brand new battery installed (2 weeks old) and both the battery and alty tested GOOD at partsource (autozone for you guys in the US)

 

try cleaning the grounds, cheking all the connections, batter terminals

If all is well, then you got a BUM ALTERNATOR, sorry dude.