After my VQ35 swap 2 years ago I have been through my original and two junkyard alternators. I cant figure out why my car would just eat these up. My idle is a little low 500rpm or so, Im not sure if that has anything to do with it. Any ideas?

 

Do you have a system in your car? If so you might try checking all your grounds, and getting a capacitor?

 

Check your voltage at idle, and at 2500rpm

Idling at 500 shouldn't be too much of a trouble, so long as your regulator works fine. Do you play a sound system at this point as well? If so, that could very well be your problem.

Alternators must stay clean, oil, water and dust can destroy an alternator. Mainly oil, since it is dielectric.

-Andrew

 

No system to speak of Sony GT300 Deck and replaced OEM Speakers with Infinity's. I also have an Optima Red Top.

 

There arent any oil leaks in my engine bay. The alternator is clean.

 

It might just be that the junkyard alternators were JUNK. Try putting in a New Unit. A Nissan Unit is $214 + $75 core. I think thats worth the money since a junkyard unit is probably running you $50-$100 anyway.

-matt

 

The first replacement was out of a 2k1, had it tested at Autozone, the next was out of a 1996, again tested at Autozone before install. I really hope its the alternators, but after 3 of them Im not so sure.

 

well, it could be that those alternators were at then end of their life and it just happened to you. I know a replacement alternator(new) might be waste of money in your eyes, but you have to try with a new one first and see how long it lasts. get one from a specialty alternator and starte rebuild company. I got my alternator for $140 cnd(rebuilt) + $50 for the core. I'm sure you can find one company in some industrial section near u. Good luck

 

Ok just took the 5th gen alternator that I thought was bad to Autozone, it checked out good. Knowing Autozone doesnt hire the most knowledgeable people I took it to a shop that rebuilds starters and alternators. Again it checks out good. He even took it apart and said the internals look brand new. Just as I was thinking, this problem isnt related to the alternator. Hopefully someone here can chime in on this.

 

Could be a bad battery ?? I know yours is a brand new Red top and they are GREAT battery's, The best, but just bring it back and get a new one to eliminate that. There is a slim chance is the battery.

-matt

 

go over all your grounds......u never know

 

DEFINATELY check grounds. Check MAF ground, block ground, head ground...maybe even buy an Ebay grounding kit.

From previous experience...poor ground can cause an entire cars electrical system to fail or go on the fritz.

 

I really doubt it is the Red Top. I replaced the Never Start with the Red Top to trouble shoot this problem in the first place. I have a Blehmco Grounding kit. I suppose I can check all of the grounds on that just to make sure they havent come loose or something. Thanks for all the input.

 

So whats the scenario thats occuring? Is the car dead when you come out to it? Do you see dimming lights while driving?
If the car is dead when you come out to it, it sounds as if something is pulling power continously, even when the car is off.

 

Sorry I should have been a little more detailed about that part. It dies at idle when there is full current draw (i.e. ac on max, stereo on, lights on......)

 

Sounds more like a IACV issue to me. Do your stepper motors work for the a/c and p/s? work?

 

The IACV is hooked up and working. There was a problem with the IACV at one point, but it was a cracked hose. This is definately a power issue. I have to get the car jump started after it dies. Im not sure what you mean on the other.

 

Get a volt meter and carry it with you. Periodically check your charging voltage, (13.5 - 15V) and your battery voltage when the car is off (~12v).
See what happens to your voltage levels when the car dies. Is the battery dead? Does the alternator charge after your jumped? Does the alternator stop charging from time to time?

Your going to have to troubleshoot your charging system. We can only guess whats going on, you need to watch your voltage to actually see whats going on. Maybe invest in an in car volt meter or hook up you volt meter so you can continously monitor your cars charging system to see when it fails.
Once it's failed, troubleshoot it until you find the problem.

 

Bet. Im not really looking for a hand out on this. I know there is going to be some trouble shooting. The info you provided is great. Im electrically handicaped.

 

You said your car idles low (500 revs) and you said it dies at idle. That sounds like your problem. Your alternator probably turns off when your idling (alternators need a certain amount revolutions to actuall run). It'll be hard to tell if this is the issue with a mutimeter since the battery will slowly discharge. The best way to check this is by jumping your car and then disconnect the battery, you have to keep your foot on the gas. Let off the gas and let it drop to idle and see what happens. If it shuts off when it drops to idle then your idle is too low.

 

When I junk my maxima, I wouldn't want them to sell my alternator to you!

 

When you junk your Maxima I dont want to buy your alternator. I have 2 now.

 

This is what I am thinking is the problem. I can sometimes catch it starting to die and slip the transmission into neutral and rev the engine up and it will run. I think Im going to try this idea first.

 

At 500 idle and with that amount of current drain the alternator will not keep up with the demand, by a long way.
What will happen is that over a period depending on the residual charge in the battery, the battery will provide the difference, but after a matter of 1 minute to half an hour, depending, the battery will be exhausted and the system voltage will collapse and that of course will stall the motor.
Suggestion: Calibrate the idle to 700 rpm with no AC or lights etc.
Turn on all the stuff. The idle should still be 700 near as dammit.
If step 2 fails, i.e. the idle drops to 500-600, you need to investigate the throttle control beginning with the IAC.
If the problem persists with the idle at 700, check for belt slip and I assume there is no underdrive pulley fitted?

 

I do have an underdrive pulley. Motostrom. I dont think there is any belt slippage. Thanks for the help!!!!

 

Yep, that's the reason, the underdrive pulley plus too low an idle speed. Raise the idle to say, 750-800 and the problem should go away.

 

Did you mention the underdrive before?

Most underdrive pulleys underdrive by 15-20%.

If that is the case, your low idle combined with underdrive simply equates to your alternator not spinning enough to keep up with current draw.

Raise idle for sure.

 

If the Red Top is a deep cycle, regardless of the underdrive pulley and idle speed, you will need a larger amp altenator to keep up with the deep cycle battery, did you have this problem before you put the battery in? If not I'm 90% positive you need to either get a larger amp alt. to match the deep cycle, or just get the largest CCA battery you can fit in the car.
- I've been through the altenator deal dozens of times, 1600watts isnt easy on them.

 

Dubbya, from one VQ35 swapper to another, raise your idle on the PF TB. Get a 6mm wrench, loosen the ldle locknut, and turn the screw up a little bit to get your idle to ~800rpm's with the a/c and all electronics off. Don't forget to retighten the locknut when you're done. That should put you at about 900-950rpm's with the a/c on, and should eliminate your problem. If I were you, I'd also recharge the battery as well before you drive it again. I have a blue top and that is the route I'd go if I had this problem. We have almost identical setups (VQ35, grounding kit, motostorm UDP, etc), but I don't have an IACV or auto tranny. I know that the ground isn't your problem since you have a grounding kit. I am 100% sure that the idle is your problem.

 

check the ground of the battery or the connection of the ground prong on the battery. It may seem like it's on nice and tight, but really it's loose. MY car was the same and I just had to make sure it was tight again. My car was shutting off every time i came to a stop or put the clutch down because of it. I had the A/C going also at full blast with the radio on(mini road trip)