03 Galant 2.4L

Hello, i am having a lot of trouble trying to figure out what is wrong with my speedometer. I have replaced my speed cluster, and speed sensor. Also, my odometer, cruise control don't work. My fuel gauge is beginning to fail also. Some days when i turn on my car the needle will slowly drop, then the next time i turn on my car it will go back to normal. Could that be with the ECU or loose wiring?

Welcome 2 TGC. I don't know much about the gauge cluster, someone else can chime in that as swap it out before.