i am having major electrical issues , doorlocks stopped working , no radio , no interior lights unless key on , no headlights unless key on

 

First off, start by cleaning the battery terminals. Be sure to check the ground straps, one on each side of the engine block. In addition, you will find one on the drivers side / passenger side fender, next to the battery. I believe there is one on the drivers side frame rail behind the plastic wheel liner. Even if they appear to look good, remove and clean them, you may have intermitent power to the ECM.