2001 Kia Spectra 4 cyl Front Wheel Drive Automatic 127000 miles. Recently I had both belts (power steering, which had broke the alternator) replaced. I thought that I had accomplished something. But soon as I drove it, I noticed a screaming screeching sound when I accelerated till about 40 mph when it changed gears and it did this when I slowed down, plus when it did this the head lights would dim. A couple of months passed and then my new alternator belt broke. I assumed it must need a new alternator, so I replaced the old with a new one thinking this should do the trick. Unfortunately it only seemed better at first but after driving it about ten miles it went back to belts squalling and head lights dimming again. I talked to some buddies and as far as anybody can tell they think maybe some electrical problem causing this. Any suggestions?
If the belts are squealing the chances are your belt is slipping and if its slipping on the alternator it won't charge the battery properly and that will cause the lights to dim. Make sure you have the belt properly tightened and the pulleys are lined up and turning straight.