Alternator problems! Help!!

[EZcheese15]

Ok, so here's what's going on.

My alternator and brake light keep flickering. It's getting worse and worse. However, the car *never* cuts out.

I checked the battery voltage. It's about 13 V. With the car running, I get 13.9 V (from the alternator to battery ground), and 13.6 V off the battery. According to the FSM, the alternator should regulate voltage between 14.1 and 14.7 V. I also checked the resistance between the alternator and battery, and get 1.0 Ω. I can't find a value in the FSM to compare this against, but it seems reasonable. Is the fact that the alternator is producing 13.9 V instead of 14.1-14.7 V a concern? Should I pull my alternator off and have it checked?

According to the FSM, the alternator light illuminates under two conditions--excessivly high voltage, or zero voltage. Is it possible that the alternator is flaking out and not producing voltage irratically?

I refuse to believe it's the alternator. I just replaced the thing less than a year ago. Is there any other possibility? Is there any other tests I can do myself that does not involve paying a dealer to use the consult? I'm afraid my car is gonna die if this keeps up. And I don't want to be stranded!

BTW, for those of you who don't know me, it's an 02 Sentra, 2.5 L.

[NISTECH]

torry run down to autozone and do the complete charge system test with the midtronics tester. Same tester we use at the dealer. Almost all facilities are using this tester now. I strongly feel its your altenator , but on a few occasions I have seen a battery cause this. regardless it is charging system related.

[EZcheese15]

I went to the local autozone and they tested the battery, and it said ok. However, the tester they had did not do an alternator test. They just had some little junk portable one.

The guy there said I have to take the alternator off to have it tested. But then again, I garuntee I know more about cars than him, so I'm sure he was wrong.

[NISTECH]

The mid tronics is a portable hand held tool. He probably didnt know how to use it. You have a kragens/schucks/ what ever the last one is around there.

[EZcheese15]

Ok, new update....

My car is cutting out on me.

So here's the problem. I'm about 99.9% sure my alternator is toast. However, that's not my issue.... I can replace an alternator, no big deal.

The problem is that my car eats alternators about once every 10-12 months. WHY? WTF. I'm literally on (i think) my 3rd or 4th alternator. And now it's dead. I am trying figure out why in the hell my car keeps killing the alternator.

Here's some background...In early 2003, my alternator shorted out somehow, fried the ring terminal on the end. It also blew the 120 A alternator fuse in the fuse box. I replaced the fuse, put a new connector on the harness, and it worked fine. About 6 months later, my alternator shorted out again, and burnt the ring terminal on the harness, but didn't blow the fuse. So I replaced the alternator, put a new terminal on the harness. Ran fine for about 10 months, then the alternator died, and burnt the connector AGAIN. I replaced it *again*. It has run fine for about 14 months now. However, now the alternator has once again failed. But this time, no contacts were burnt, no fuses blown. It's just not producing power.

WHAT THE HELL IS CAUSING MY ALTERNATOR TO SHORT? It's driving me nuts, I can't figure it out. I want to just replace the harness, alternator, battery, the whole shibang. However, The harness alone is almost $500. WAY more money that I want to spend.

Is it possible my harness has too high of resistance? Its the only thing I can come up with, but I don't know how right I am. Basically, I'm looking for some alternative ideas. Or how should I replace the harness? Should I pull it out of the car and actually splice in my own wire to replace it? Basically fix my own harness. I'd rather do that then dump $500 on a new harness. But I want a second opinion on whether or not that might fix it before I spend a whole weekend ripping the harness out of my car.

[NISTECH]

Torry give me the run down on your car. What engine mods do you have. What electrical mods do you have in the car. Big amp? high out put player? This is along the thinking of to much electrical load for your alt to handle under extreame conditions. Also do you have hids?

The engine mods I am thinking Header possibly overheating the alt. Do you have any type of shielding between the header and alt?

[EZcheese15]

I have no electronic mods. My mods are the following:

HeaderCat-backCold Air IntakeRemoved Balance ShaftsKnock sensor replaced with resistor

I pulled the front end of the car tonight. I pulled out the fuse box and unclipped the wiring harness back from the alternator to the fuse box. I haven't unraveled the harness yet to see how far back the harness has burn dammage, but I plan on doing that either tomm or saturday.

I am fairly certain after examining the harness today that the harness is causing the alternator to draw too much amperage, thus causing a shorter lifespan. My plan is to run an alternate alternator power wire from the fuse box to the alternator. I will zip tie it around the harness (much easier than actually splicing it open to remove the old wire).

Anyway, I'm gonna drop off my alternator to have it rebuilt tommorrow, and also pick up some wiring and connectors. I hope to have the car back on the road Saturday. I'll keep you posted.

Torry

Oh, yeah, one more thing...I noticed the 4 bolts that hold the alternator together were missing when I took off the alternator tonight. So basically, you can spin both sides of the alternator independently of each other. However, I don't think this has any effect on the problem, because the dog ear flange that the alternator bolts on to would keep the alternator together anyway. But I *will* be taking it to a different rebuild shop this time.

[NISTECH]

Torry is your header wrapped or sheilded from the altenator in any way? It sits right up behind it , you need to have some sort of heat sheilding there.

[EZcheese15]

Torry is your header wrapped or sheilded from the altenator in any way? It sits right up behind it , you need to have some sort of heat sheilding there.

No, it's not. I will pick up some header wrap tommorrow as well. Thanks for the suggestion.

[NISTECH]

That extreame heat right there might be whats causing the alt to fry. Its probably overheating the electronic regulator inside it.