07 ram won’t start

Hello, answering here and see you asked twice, so will just refer to this answer. I don't see any reason that a simple radiator replacement would cause the flashing light and other concerns. I think there is more going on. Either some kind of wiring was affected, the battery could be dead, the wrong key could be getting used (not programmed) or something has failed in the electrical or engine performance area. There are too many questions to ask and be answered about this concern in this forum, so I'd urge you to get assistance at a shop near you. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops