I wouldn't think that a loose connection in the instrument cluster would prevent the vehicle from starting. (I could be wrong). I would be checking the battery connections.
If at first you don't succeed, get a bigger hammer!!
2005 Dodge Grand Caravan SXT (3.8L, purchased at 108,000kms. Now at 166,000km and counting)
1997 Dodge Caravan Rallye (3.3L 242,000kms)
2002 Chevrolet Cavalier (Base Model)
1988 Ford Ranger (2.9L 2wd)
1973 Dodge Cornet Wagon (318 cid)
1965 Rambler Classic 550 4 dr (232 cid)
1966 Rambler Classic 55 Wagon (232 cid)