I have a 05 Kia spectra the problem is. When I start the car everything is fine but after 15 mins of driving the speedometer stop working it has new speed sensor and new cluster so

Ground number G12 which is under the master cylinder on the inner fender is the ground point for the speed sensor. Make sure its clean and paint free if you have not already. There are 3 wires, power, ground and signal. The signal wire goes to the instrument cluster via a few connectors. I would get a wiring diagram of the speed sensor and find the few connectors it goes through, make sure they are good and clean, check continuity of the wire to the cluster, then leave it apart and check continuity again when it quits working. One of the first places i would check is where the signal wire runs through the fuse block under the hood

Did you find the problem? I have the same problem

out speed sensor When heated stops kilometer

Mine did the same thing. They changed the cluster 4 times. It does it every once in a blue moon. Drives me nuts!

https://youtu.be/0epPf9qJ9bI