It's probably a cold (broken) solder joint on the instrument panel. It happens. I'd remove the instrument cluster and reflow the main solder joints, especially around the connector, if you're comfortable in your soldering skills. For me, I'd just send it off to a rebuilder. I like these guys (partially because I used to live 5 minutes from their shop and have visited in person before) and can vouch for their work, but there are plenty of others if you search google and ebay. Most sell the service through ebay. It's usually around $50 for the service. Search ebay for "windstar instrument cluster" and see what's there.
http://masrepair.com/
http://stores.ebay.com/AIRBAG-MODULE-STORE