Instrument cluster comes on after van warms up .
How about before it warms up?
I happen to own a 1996 Dodge Caravan (bought it new). I was experiencing a problem with the cluster becoming intermittent and had temperature related issues. It was an aging issue, kind of like my intermittent sore hip and knee some mornings.
It was about a 20 minute very easy job to remove the cluster, reheat some solder joints (I could actually see cracked solder) on the back side and re-install it. Voila! Problem solved!