Battery issues on 1997 Dodge Ram Van 3500

Battery goes completely dead; put new one in, 3days without starting will not kick over. We even put a solar trickle charger on it.

Asked by for the 1997 Dodge Ram Van 3500
You have a severe parasitic drain. In other words, either the engine control module is not going into sleep mode and drawing more power than it should. It could also be an aftermarket radio not shutting itself off too. Double check that the dome lights aren't staying on.