Hi I have a 2004 Dodge ram that is driving me crazy. I have no interior light when I open the door, if I put the key in it all works again. The same for the remote door lock if I am outside the truck nothing but as soon as I put the key in it works. The funny part is that sometime it works

And last the radio, it went away a while back. Sometime it will come back but not for long.

 

Go check all your fuses for one that might be loose or partly blown

 

I had the same problem my stereo started going out, the came back on, then I noticed my remotes wont working and I had no power when my truck was off. Finally nothing came back and I started looking for a solution. One of my fuses was broken it was number 51. I have a 2003 dodge ram so its probably the same as yours. Try finding that fuse, it should be a 20amp fuse.