JMag90

Hey All,

I have a 2001 SE Anniversary in which I just replaced the alternator myself to save a few hundred bucks. I went with one from AAP which I may now live to regret.

After getting a ton of help in the "newbie questions" thread from DennisMik (Huge thanks to him) I finally narrowed the cause down after a crapload of testing.

Long story short: The battery and brake lights flare up and the car shudders heavily at high RPM's (over 3k is the worst). Unfortunately the alternator passes with flying colors when I actually take it to AAP.

After another day of jacking the car up and checking the belt and idler pully I was moving the alternator harness while the car was on and the voltage meter and lights were going crazy.

I found that just tapping the alternator with a long wrench caused the same behavior.

So I guess I'm down to these possibilities:

1) Alt is bad and vibration causes the brushes to stick
2) Harness has a loose wire and is causing a lot of electrical problems
3) The case of the alternator is not grounded well enough (even though it never came with any sort of ground wire as far as I know).

As much as I'd like to check the harness I don't even know how I'd begin to get that thing out far enough to open it up... It has about 2 inches of movement even when it's disconnected.

Also if it is the alternator how do I prove to AAP that their alternator is bad when their test says fine?

Thanks a ton guys!

DennisMik

iTrader: (2)

Thanks for the kind words.

If you tap the alternator or wiggle the wires going to it and the alternator output goes kaput, maybe the connector in the alternator is the problem. About the only way to check that would be to take the alternator out so you could inspect it closely. But even then, the problem could be on the inside of the alternator, so it may not be visible. But you could at least see if the contact pin was pushed down into the alternator.

As for the wire harness, it is a short, separate section of harness. It has 3 wires in it - 2 for the alternator and 1 for the a/c compressor. It is maybe 12 inches long. It plugs into the main harness on the bottom side of a bracket that hides the connector that is located above the a/c compressor. The part number is 24076-4Y900, list price $45.23.

I don't have AAP in my area, so I have never dealt with them. Is there more than one AAP store in your area? If so, take the alternator to another store and explain the situation to them and maybe they are more reasonable.

Another thing you could try is take the alternator to another parts store chain and see what they can find. You probably have autozone, but those people would be lucky to find the door if the store was on fire.

Kristoefur

iTrader: (4)

I recently went through a similar alternator experience.

2003 Nissan Maxima GLE 115,000 miles.

Driving home from work one day my car started acting weird. The engine power started to cycle up and down and finally came to a halt on a side street. Before the car died I noticed the lights on the dash (brake light, airbag light, ect.) flickered just before the car shut down.

At first I was confused as to what happened. I thought maybe my car did it's last swan song and passed away. But that particular drive home wasn't anything out of the ordinary. I was cruising at about 40 mph when she lost power. I tried to start the car up and NOTHING. It didn't even turn over. So immediately I thought the battery died. But that didn't make sense because I was driving the car. The alternator should be charging it.

I had my wife come give me a jump and low and behold the car fired up. I drove it down the road about a mile and it died again. So, I had my wife jump the car again and made it home where I could take out the alternator and have it tested. I took the alternator to Auto Zone where they tested it and it came back as a good working unit. I also tested the battery and they said it was bad. So I return home and re-install the original alternator and replace the battery with the new one.

The car starts up and run fine for about 10 mins. Then boom, NO POWER. At this point, I'm frustrated because I know the culprit is the alternator, but Auto Zone said it tested good. Once again, I take out the original alternator and go back to the store and ignore the customer service managers advice and install a new Delco alternator and BINGO. The car starts and continues to run. I tested the battery and it holds 12.5V when the car is off and roughly 14.5V when the car is running.

Long story short: I learned that Auto Zone's alternator testing machine is not always accurate. My original alternator tested to be okay, but was in fact dying a very slow death.