If you're having an electrical problem with your door (e.g., power locks not working, dome light not coming on), you'll need to consult your owner's manual. It will have a fuse diagram showing which fuse(s) control the specific door circuits. Common culprits might include fuses for the power locks, power windows, or the body control module (BCM).
If you can't find the relevant fuses in your manual, you can also find a fuse box diagram online by searching for "2003 Dodge Ram 1500 fuse diagram". Many websites, including repair manuals sites, offer these diagrams. Remember to always disconnect the negative battery terminal before working with fuses or electrical components to prevent damage and injury.