the truck starts and drives fine but when I remove the key the abs light is on but very dim, over drive light is on, gauges flicker on an off and the doors sometimes lock and unlock sporadically. Everything works properly when the key is on. Not sure what to start looking/testing at first

 

Do you have a water intrusion around the fuse box? Leaky windshields are a common problem and you might need to dry that area out and get your windshield resealed.