What causes a 1989 Dodge Ram 250 TBI Van not to start or turn over when the battery is charged and the alternator was replaced and all the electric works when the key is turned on?

Check the transmission neutral switch or the connection to it. The neutral switch is on the lower left side, beside the kickdown rod. There is also a connector in the wiring harness on the right side of the engine, at the rear of the right side valve cover. If the neutral switch isn't functioning for any reason, the symptoms will be exactly what you described. I once did some engine work on my 88 Maxi and forgot to connect the neutral switch in the harness, so I speak from sad experience...;-)