1994 dodge caravan won't start

Well we are at a total loss as to why our van won't start. Two times previously we got in the van, went to start and nothing happend. We jumped the battery and it started. Now it happend again only this time jumping did nothing. The van is totally dead. The only sound you hear when you turn the key is the starter relay buzzing. We had the starter and solenoid checked at a local parts dealer and it was fine. We changed the relay and bought a new battery. STILL nothing. We used a 12 volt tester and check the conections to the starter and they were fine. We are open to any suggestions that any experts on dodges would have. We thought it may be a fusible link but the connections to starter have power sooo. PLEASE HELP!!!!!