Parasitic battery drain?

Few weeks ago after leaving sit over weekend battery was dead. Replaced battery, worked fine for a few days. After that occasionally the remote start would not work but would start perfect with the key except after starting I noticed the radio station was reset like the battery had died. Once tried starting and would not start just one 2 second click sound. After 3 attempts it started but the anti theft light was on. Shut off, restarted and was fine. Now my remote start does not work at all and most mornings when I start with the key it fires fine but again radio is reset like battery died after trying the remote start. Checked all fuses fine, no lights or switches left on.