For the last couple weeks, the warning chime will go off and interior courtesy lights will flash will driving. There are no indicator lights in the instrument panel that come on and gauges are all ok. Anyone have any ideas?

 

Sounds to me like it may be a door ajar switch that is failing or out of adjustment. If the truck body flexes right, over a bump or such thing, the door can sometimes move away from the switch just enough for it to think the door opened for a second. This has been fairly common on older vehicles but I'm not sure exactly how the door ajar switch works on a 3rd gen. Previously they could be adjusted by pulling a small plunger out of the tip of the switch.

To diagnose this, get in the truck, start it up, and lean on each door to push it towards the open position to see if you can duplicate the condition.

 

You might want to check this out. (http://dodgeram.info/tsb/2003/08-004-03.htm). This problem has been around for a while, but I have not read of any definite solution to this problem. Most have had re-flashes done to correct this problem.

Shawn