Ok so I am new to this so dont everyone yell about where I am posting. So I have a 98 f150 that the alarm goes off when ever it wants some times its 30 mins after I lock my truck the last time was 2 days after I locked my truck. I disconnect the batterys now everytime I get out of because I dont want to have to come running back to my truck to put the key in the drivers door to shut it off. let me know what kind of information anyone needs and ill get it. what i got so far is when the alarm goes of the interior lights arnt on so wouldnt think door switch, i do not have a key fob so i wouldnt think that would be the issue.

 

Do you have other strange electrical things happening....like wipers coming on by themselves? Or dash lights not working or half of them not working? any dash lights on/flashing when this happens?

You MAY have a front windshield leak....water is migrating to the inside and dripping on the GEM module