Q: 95 nissan automatic truck wont shift out of first gear

If the car can shift manually, then you likely have a problem in the electronic controls. If you can get your hands on a scan tool to read the transmission controller, it will help get you moving in the right direction. Since the car is a ’95 the universal scanners will not read it. I think the first move should be to look at the transmission wiring harness and all the connections. There may be a place where the harness can get loose and contact the exhaust manifold causing it to burn and loose connection. If the controller is not getting a VSS "Vehicle Speed Sensor" signal, it will not initiate a shift. Beyond that, I suggest you contact Your Mechanic. They can send a technician to your home or office to check out your Nissan Truck and let you know what can be done for it.