Cadillac Repair: no battery light is on 1990 eldorado, test procedures, eldorado

Question
yes my battery was going dead every couple of days no light was on pulled the alt and took it to the local parts house they checked it and said it was bad replaced it and now the no battery light is on and no charge is coming from the alt i even took the new alt back and had them ck it they showed me and it was putting out about 13 volts on there machine so what should i do next

Answer
If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL MULTIMETER, Simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.