Have to agree with Airjer. Unfortunately the "bash the dash" test isn't entirely conclusive. Sometimes the bad solder joints can be there and the bash won't jar them enough. Eye's on the joints is the only sure test to verify they are good or bad. Even then you might want to reflow the joints no matter how they look. Some of the cracks can be beyond tiny. Here's a slide show on how to get at them and fix them:
http://photoshow.comcast.net/rlshaull/
Beyond that you may have a Body Control Module (BCM) on it's way out. It controls most of the electronics in the van including interior lights and instruments. Does the cluster pass the self test? Hold the trip and reset buttons in with the key in run.