350zDCalb

iTrader: (21)

Figured this was the best place to ask this question.

Just wondering if this has been seen in many other forced induction/high hp 350z's/G35's from excessive heat...

I had to replace my alternator about 3 months ago, stock one dies, had a few hours warning, the battery light flashed periodically, then came on solid, then I was walking.

So, 3 months later, a few days ago, the partial throttle cruising is a bit choppy, almost like it is misfiring, notice my dash battery light is flickering as I accelerate, and the factory voltage meter drops at/ slightly below 12v.

I have already checked all connections to alternator, starter, battery, belt tension. No sign that the belt is slipping, but I can usually only make the dash battery light/voltage drop occur when revving it wuickly to 5000+rpms, then it seems like after it heats up, after driving for a good 10 minutes, it will present the same symptoms intermittently at various rmps/verious loads...my conclusion- swap in a new alternator...

Any ideas, prior issues with your alternators failing?

Thanks

failsafe306

iTrader: (38)

Have you made sure the 12v wire going from the alternator isn't damaged or burned anywhere along the line?

Jay'Z

iTrader: (118)

My alternator is fine.. But I would check the battery connections are strong.. You should have almost 14v most of the time..

350zDCalb

iTrader: (21)

inspected all the lines, everything checks out... i figured something was loose at first, since the intermittent nature of the problem... but i am starting to think that heat is killing my alternators, i know a common problem on some other F/I vehicles some friends of mine own...

keep the feedback coming, thanks

350zDCalb

iTrader: (21)

it makes 13.9V when checked with an external voltmeter, but at the certain times that it drops the voltage, per the stock in cabin volt meter, it shows 12v or a bit under, as if the alternator completely shuts down for those moments

all connections to battery are good

Jay'Z

iTrader: (118)

You may need a batt with higher cranking amps.. Or a better alternator.. Do you have a system too?

failsafe306

iTrader: (38)

I'd disconnect the 12v line from the alternator and meter the resistance on both ends, and try shaking the wires around to see if the resistance changes. The copper on the inside of the jacket could be damaged and get worse when it heats up.

Just a thought

failsafe306

iTrader: (38)

Oh, and have you tried a new battery? Electrical problems suck....

350zDCalb

iTrader: (21)

I do have a system, have a capacitor, even though I've heard they are worthless, to some saying they are great and will resolve the problem that I am experiencing. The issue occurs regardless of whether the stereo is on or not

The battery holds its 12.5V consistantly, and, forgot to mention, replaced the battery 3 months ago as well, at the same time as the alternator

350zDCalb

iTrader: (21)

3 month old battery

superchargedg

iTrader: (4)

I can see high heat possibly melting the copper wraped around the stator inside the alternator,but where it sits it should have enough air flow to not be a problem.If the next alternator fails i would take it apart and see if anything was melted.

Jay'Z

iTrader: (118)

Battery specs pls??

failsafe306

iTrader: (38)

The battery voltage should be higher, closer to 14vdc. Did I read right, that you checked the votage coming off the alternator itself?

350zDCalb

iTrader: (21)

soory, 12.5V when the car is not running/alternator not spinning

13.9 with car running

i always thought an alternator typically works ot it doesnt, so hopefully it is some line somewhere, i'm still searching, i hate electrical problems.

350zDCalb

iTrader: (21)

oh, sorry, nothing too fancy, Autolight platinum 96P, better than the factory battery, but not anything outragous, thing is, no issues like this for a few years on the stock battery, and 3 months now on this one...i dont think that is the determining factor here...

failsafe306

iTrader: (38)

Sounds like your battery. It should be holding 13.9, even with the car off.

Jay'Z

iTrader: (118)

Actually the factory batt is better than u think..

I couldnt find that batt... When I say specs I was asking how many CCA (cold cranking amps) and RC ( Reserve Capacity)..

350zDCalb

iTrader: (21)

Think you are right... I just tested somethign i hadnt yet...

I disconnected the wire coming fromt he alternator to the battery, testing that by itself, it reads 15.5V.

I turned the voltmeter so i could see it as i got in my car to rev it up...as i revved it, the alternator read up to 16V..so the alternator is not cutting out intermittently as it appeared... guess the battery sucks,

who has experience with a good battery, recommendations?

Thanks

350zDCalb

iTrader: (21)

yah, seems like it, what kind of battery do you run?

350zDCalb

iTrader: (21)

what are the specs of the factory battery? CCA/RC?