Wife's xa has been acting up, she told me her battery light had turned on twice while driving in the past 2 weeks. Today when she got out of work car wouldn't start. Everything turns on (radio, lights etc) but car just clicks and doesn't turn on. We tried to jump start it and it would still not turn on. I checked battery with meter and it read 11.43. When the car tries to turn on all the lights dim down. Is it the alternator? I just changed the battery less than a year ago. Car is 06 120,000 miles.

 

Batt voltage should be over 13v. I would charge the battery and recheck the voltage with the car off and running. Running voltage should be higher maybe 13.8 to 14 or so. Also check if you get a drop with the lights on, you should get a bit of a drop but not much. If you get a higher voltage with the car running the alt is probably ok. This is a very cursory check of the alt but will give you a clue.
P.S. Just an opinion but I would only jump the car in an emergency, its always better to charge

 

You can Always remove the alternator and take it to autozone to have the test it ITS FREE

 

Make sure the belt is tight and the heavy red wire is not loose, also check your battery terminals since they have been removed a year ago, if they are not tight the battery will not charge even with a good alternator. Check the chassis ground from the battery too. If everything is good then chances are the next likely thing is worn out brushes in the alternator.
Recharge the battery right away to prevent damage to it!

 

A fully charged, healthy battery should sit at 12.7V or higher. Brand new batteries should sit at 12.8-12.9V. As they age, their charged voltage drops. With the engine running, voltage should be at LEAST 13.3V, 13.8V is the regulator set point on the stock alternators. Less than that would point to an alternator problem. Make sure your alternator belt is not worn out and properly tightened, check for loose or dirty/corroded battery terminals.

Jan is right, put your battery on a charger and bring it to full charge, leaving a lead-acid battery at less than full charge drastically reduces its life due to sulfation.