2000 Dodge Ram Engine will not crank

Have you tried cranking it in neutral? Can you tell if there is a load on the starter circuit, with the key in the crank position? The lites may dim or take a reading across the battery posts, see if the voltage reading drops a volt or two below ocv. If there is a starter relay in the power distribution center, you could do some testing there. The voltage to the load side of the relay, should be hot all the time. The voltage to the control side, goes hot with the key in the crank position. Any testing make sure the tranny is in park or neutral and the e-brake is set.