I have to keep my truck pluged in all year or it doesn't have any power,if I leave it sit all day I have to start it about 30 minutes before I can drive it,any ideas on what's wrong with it?

See if the diesel troubleshooting steps below offer any help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281