Battery Light on HELP please
 

Background info 2006 Ford Focus ZX4 SES 2.0 86k miles. Light came on less than a week agoso I tested at that time a discovered the alt was not charging voltage was steadilly dropping on the volt meter. So logicall replaced the alt on Saturday drove fine Sunday, Monday, and Tuesday until 6pm then the light came on again. Checked voltage and it was at 14.2 running with the light on and at 14.1 running with the light off. Yesterday the light stayed off on my way to and from work but at 6pm again when we went out it came back on. Today the light came on on my way to work. So after sitting for 4.5 hours I tested the voltage and the battery read 12.6. That tell's me the battery and alt are both fine. Help me out what am I missing and how easy is it to fix? I am frustrated because I have no other symptoms going on other than the light is on. I have been driving with the radio off since Tuesday. I also disconnected my amp on Tuesday night to rule out a draw from the amp. So four altenator's later I am finally charging correctly. First (original) one not chargeing, second over chargeing, third not charging, forth finally charging at the correct voltage and amperage. Also replaced the pig tale, this was replaced before the third altenator. I have also repleced the battery just because. Someone please tell me why my battery light will not go away? I am getting ready to cover it with electrical tape I am so pissed off right now I can not think. HELP I AM REALLY FRUSTRATED RIGHT NOW! Thanks for any more advice and suggestions you can give me. All work was done by a ASE Certified tech and eveb he is confuse as to what is going on currently.

Were all of the replacement alternators aftermarket meaning none were purchased from Ford?

Yes all were fron Delco. I do not see a reason to pay 350+ for an alternator from ford when I can get one for 180.

For $350.00 you should be able to buy a NEW alternator. We usually exchange for a rebuilt and it should cost a heck of a lot less.
I can agree with not wanting to pay what seems like extra for a Ford alternator, but how much extra have you been paying with the ones you so far have purchased.
There have been loads of problems with aftermarket alternators for Fords. Just trying to save you some trouble.

I know you don't need this now , but remember you get what you pay for !!

I know. Thaanks for taking the time to help me with this. I have installed a new aftermarket one not rebuilt. The wierd part is the car drives just fine no surging, no other lights, radio, wipers, headlights all work fine. The voltages are great 14.3 when charging 12.6 when off. I just do not understand. I also checked for a short and it appears that I do not have one. Quick question though. My stereo is no longer utilizing the left speakers. I ran new wires to all speakers in December. The stereo is 2 years old could a stereo that is going bad cause something like this? I know it sounds rediculious but stranger things have happened to me.