my battery is not charging right

i have a 1993 Ford Explorer my battery light on my dash board came on and i was able to drive like that for 2 days and i replace the alternator and the battery light went off the next day after i replace it the needle on the dash board kept moving to the left and then it went dead so i replace that battery with a brand new battery as i was coming back home tonight my heads light,dash panel was getting dim i had turn my head light off while i was driving and when i turn it back on it felt like all the energy was suck out as and it went dead for the alternator it was rebuilt not new and for the battery 700 cranking amps can someone help me out before i go crazy

 

If the alternator was installed correctly, I would look at your battery/alt/starter cables very well. They have a tendancy to corrode.

 

i had the alternator recheck to see if it was bad was not,i replace the postive cable from the starter to the battery brand new as for the negative cable the wire inside the cable is old and brown corrode looking as for the battery it is brand new with 700 cranking amps