alternator wont recharge battery

I have a 95 m/m 2.4l, I have been having some charging issues off and on for some time, my alternator is not charge my battery i took out my alternator and had it check out was told this it was working find, so i put it back in to find that it was doing it job again. it was working fine for several weeks then started to have the same problem again again i took out the alternator to have it tested again it test fine but i replaced it anyways. (fyi i replaced my battery the first time i tested the alternator) once i replaced the alternator made sure connections were tight and no blow fuses things were working great for over month or so but now here we are again same issues as before alternator not charging battery. Any help would be great let me know if there is more info needed to come up with a possible solution. Thank you in advance for any help that is given. Aaron

Welcome to the site..

1 Is there any lights on on the dash?
2 do you have a Volt meter?
3 have the cables to the battery ever been changed?
4 is there a ground wire between the engine and the cab, if so clean it
5 how do the wires look near the alt. are they hard as a rock or flexible?
6 In the manual section, you will find the UTI training manuals. In there is an electrical section that will help you. With a volt meter you will be able to find the problem. Please take time to skim through it. It will show you how to check for voltage drops. If you don't have one go out and get a half way descent digital one.
Charging voltage at the alt. 14.2VDC voltage at the battery will change depending on the charge of the battery. The more discharged it is the lower the voltage is at the battery. But the alt. will be 13V to 14V
7 are the light nice and bright or are they like a couple of candles in a can?