2002 Ram 1500 Interior Electrical issues

Two weeks ago the radio started to short out on me for a few minutes and then worked normal again. This week the electronic odometer had no green lights for a couple of days and no it's working normal again. Now, the interior lights don't come on when the driver's side door is opened. I'm also having similar issues with the passenger side window controls and the rear door locks not working. Could this be a sign that my battery is going out? I have already checked the fuses and none of them are blown?

Any suggestions?

I'd get it scanned for body codes but I'm not sure all the chain type auto parts stores have scan tools to see body codes.

What are body codes? I never heard of that

My mistake. Does the overhead display show "No Bus"?

Sometimes these show up as a poor battery ground and sometimes a poor body ground.

Body ground locations can be found in the wiring section of this '01 service manual,

Here's a downloadable 2001 service manual.
The download is kinda slow but worth the wait.

http://dl.dropbox.com/u/42304/2001DodgeRam.pdf

There are no unusual readings on the overhead display.