dead battery

Hi everyone, Purchased an 01 Millenia back in July off of a friend. He told me that the alternator was going to need replaced. I bought the car anyways, went to the junkyard, purchased a grade A used alternator, and installed it in my Millenia with the help of my boyfriend. About 2 days after...

I changed the battery on my 06 Mazda3 and now the power door locks buttons on the driver and passenger doors dont function. Remote keyless also doesnt work, and I cant get the reprogramming methods to work. Any ideas? I need all the help I can get on this one.