So, a few days ago I noticed my car was making a "whine" noise when I started it. It did it in park and neutral. It sounded like feedback through speakers, but it was in the engine compartment. Higher pitch as I stepped on the gas, lower as I let off. My gas mileage also dropped 1mpg in as many days.

I searched all over the forums and it seems like it could be just about anything.

Then, this morning my car wouldn't start (and also had a TRAC not available and ASC not available error with ABS warning). I started troubleshooting the warnings but never thought about the alternator. After hours of disconnecting and reconnecting plugs and cleaning things and so on I asked my neighbor for a jump. He gave me a jump and the car fired right up, with the whine and the warnings. I was looking for the whine and I could smell something electrical burning, just a little bit.

So I took off the negative cable from the battery and the car stopped instantly.

So, I think I have a bad alternator. If this were an older car I would know. But these newer cars are crazy and I have no idea. Could it be some sort of attachment before or after the alternator that is the issue or is it just the alternator? I am thinking that the alternator died and that is the whine noise; it just took a few days to wear the battery down enough that it wouldn't start any longer. (just drive twice a day to/from work, total 12ish miles)

If I should replace the alternator I would love it if anyone can point me to a thread detailing HOW to replace it. I have no idea how to deal with the tensioner arms and such.

 

bakatono, from what you describe, you do have a bad alternator. If the alternator was functioning even a little bit, the motor should have continued to run unless you have tons of electrical stuff running (ie, seat heaters, dash fan on max, headlights on, etc). If you turn everything off possible and re-perform the lead lift action and the car dies again, then that essentially confirms a bad alternator to me. Granted, there are a few more checks that I would recommend.

You will need the use of a multimeter, but disconnect both of the battery terminals and then do a resistance check from the negative battery cable connector to the case of the alternator. You should get a very low resistance (under 5 ohms). If you are getting anything more than that, then you have a wiring issue. Do a second resistance check between the positive battery cable connector and the positive lead on the back side of the alternator. You should get less than 5 ohms there. If you do not, then you have a problem with the power wire and you will need to break it down some and figure out what section of wiring is bad.

I mention a possibility for bad wiring. I do not think this is what is going on in your case unless the wiring is providing a high resistance connection between the alternator and the fuse box (ie, the resistance is causing a large voltage drop and when you remove the battery, the voltage is dropping far enough that the computer can not maintain the car running). Our battery cables are known for failing and leading to a hard start condition and whatnot. They can also get very warm, giving you that burnt electrical smell. New battery cables are cheap and may be an option to consider before trying to go after the alternator.

ANother check that I would recommend is to restore the electrical system to normal. With everything electrical turned off, connect the multimeter across the battery terminals (set to VDC scale). It should read 12.6 VDC. If not, charge the battery back to 100%. Now, while starting the car, watch the multimeter. As you crank the car, the voltage will drop, but should not drop below 11.0 VDC (if it does, then you also have a bad battery). Once the motor catches and is running, you should see the multimeter jump up to around 14.4 VDC for about a minute (maybe less) and then settle out around 13.5 VDC. If the voltage is down around 12.8 VDC, then you have a voltage sensing issue. If the voltage is at 12.5 VDC with the motor running, then you have no output from the alternator and that would indicate a potential alternator failure.

Dealing with tensioner arms is easy. Get yourself a 1/2" breaker bar (the kind that do not have a ratcheting top). If you look on the tensioner, you will see a square hole at the end of the arm. The breaker bar will slide into it. PUll on the breaker bar to make the arm move to remove the tension. Slide the belt out of the way and then gently let the breaker bar move to make the arm attempt to re-apply the tension (it can't since the belt is now missing). Installing a new belt is the same process: use the bar to move the arm out of the way, slide the belt under the tensioner once the belt is on all the other pulleys, gently release the bar to allow the tension to apply tension.

 

Thanks for the info. I already ordered an alternator from partsgeek.com (BTW, i DON'T recommend this site. I ordered, and paid, for next day air, that was last week, part arrived today). I was looking at the steps to replace the alternator and I think it is beyond my ability. I could do it if I had all the tools and jack stands and someplace to drain oil (which i just had changed!) and so forth, but I do not. I would have to buy a lot of stuff to put the already expensive alternator in. So, I think I am just going to take it in and have someone do it for me. Hopefully they will test to ensure that is the problem. The local Jag guy seems pretty good.