96 Sunfire, 2.4, auto

Just joined this forum. I am looking for a solution to a charging problem.
Car runs fine, took in for oil change, ok for a couple of miles, battery light comes on, speed up rpm to 3500, light goes off. I think it is a alternator right. Speeds up more power, most likely bad regulator.
Well, I put in 2 rebuilt alternators, light still on. Put in new battery, fully charged, light still on.
What do you think.
This is me just guessing now. Is it possible that during the oil change the tech hit a wire and knocked it loose? or, it was corroded and him moving it just finished it off? What about a relay or inline fuse. Does this car have one of these in the charging circuit? OH, all the fuses are good. I checked the forum back to 4-05, saw some writing on bad ground, corrosion.

I even put a voltage meter across the battery after installation of both alternators and was only getting 11.74 volts. I am not getting voltage from alternator.

Please give me a lead here. No other problems, as I already fixed a bunch of things, ie) radio, turn signal assy, starter, plugs, ignition module with coils and wires. These thing are all just general maintenance.

Let know what you think......
Thanks

Remove and clean the battery terminals. They will corrode and cause the alternator not to charge it properly. The other issue is to check the grounds, the main one should be near or on the bellhousing at the transmission. One other thing I would check, the tensioner and the belt may be bad. You didn't say that you had changed either so you may want to look at that. Also, clean the wire lead to the alternator, they will get corroded and lose contact too.