1987 Jeep Wrangler Water Pump

what do you mean? does the water pump just not turn after you had installed it? There could be a couple of reasons. Water pump bad. something inside binding up the pump or the wrong water pump for the engine. Disconnect the belt and remove, try moving the water pump pulley back and forth, watch it sometime the edges are sharp. it it turns a little and stops then ther could be something loose inside locking it up.