Truck wont start but will with jump battery.

If you have excess drain, just about anything can cause it. Check the amp draw. I haven't looked at the specs, usually around 50 ma, that is.050. You can pull/replace fuses, one at a time. When you pull the fuse on the problem circuit, the excess drain goes away. Charge the battery. All battery connections clean and tight? Is the charging system working ok?