I have a 1995 BMW 530i..the windows,sunroof and door locks work sometimes..

Hello, This is 99% a fusible link underneath the hood. On the 5 series it should be connected to the strut tower on the side of the engine where BMW is written on the valve cover. Look around at pictures, it is common, you will see it. Replacing the fusible link will restore the central locking to its original state if broken. However, this could be an issue with water intrusion into the rear carpet that causes the wires to degrade in the harness, and you may or may not have blown fuses under the back seat. If the fusible link is good and fuses are good, it is time to go to alldatadiy.com or purchase the service manual and chase down the splices for those circuits.