Toyota Repair: 2002 Camry alternator

Question
Hello Ted,
My daughter is a new school teacher 2000 miles away and I'm trying to help her get her alternator problem resolved. She has a 2002 Camry 4 cylinder automatic with 105,000 miles. It's in beautiful shape but did have some front end body work done about 20 months ago (nothing further in than the radiator). The car has a high quality battery that's about 10 months old that replaced what I think may have been the original battery.

The alternator apparently failed last week. Car failing to turn over was the first symptom my kid recognized. The car tech teacher at her high school looked at it for her.  He ran the test on the battery/alternator, and ordered an inexpensive ($125 I think) after-market alternator for her. He and the kids in his class did the install.

Unfortunately the battery light came on immediately after the install, particularly at higher RPM's which seems odd. And when she got home  the car wouldn't start/turn over.  I don't think it quit running while she was driving.

She jumped started the car and took it back to the tech teacher (apparently the alternator produced enough juice to get to the car to school 7 miles away).  He checked the belts and connections I think, but doesn't seem to know where the problem lies at this point.  

Do you have any suggestions as to what might be going on? I did read on a blog that Camry OEM alternators have voltage regulators built to tighter specs than after market ones. Could that be the problem? Should I consider buying an Toyota OEM alternator (about $300) and having the shop class install it?  

It would be great to have your thoughts about what might be going on. Thank you for your time and expertise.  
Regards,
Will

Answer
Hello, although most of the time aftermarket alternators are perfectly ok to use there is a higher chance of getting a bad one, so that is one possibility, to be sure the charging system should be checked while the engine is running, she should ask the tech teacher to connect a volt meter or a charging system tester and see what the voltage is at the battery, I'm sure he knows how to do this so I don't understand why he doesn't seem to know what the problem is, it's very simple, either the alternator is charging the battery or it's not, a simple voltage test is all that may be needed. She could also take the car to one of the autoparts stores like  Autozone, O Reilly etc., they will test the charging system at no charge, if the alternator she bought is defective then she can take it back and get another one, they usually have some sort of warranty.