I've gone through 4 alternators in the past year. What is causing this and is there some place to get a free diagnosis?

What is your question?

The dashboard lights go dim when I use any extra power, radio, heat, electric windows, and so forth. Then there is a high pitch sound like grinding or squealing. Then the car will start losing power.the more often I have the alternator replaced, it seems they are not lasting very long at all, anywhere from 5 months to now this last one about 3 weeks. I was told by my mechanic that the computer needs to be reset and updated, have you heard this may be the problem? I have not had the computer done yet. Please help.

What makes this problem better or worse?

Normal driving, and now, short trips, it drives fine when cold however if it’s a short trip to the store, when I come out to start it, it seems like a slow turnover, but then just ticks like a bad Conection on the battery and won’t start. When I get a jump, it fires up right away

How long has your 2002 Kia Spectra had this problem?

About 8 months to a year.the alternator in it now was tree weeks ago, it does have a life time warranty on the alternator part