Why when I dim up the cluster lights my fuse goes down and no light the instrument panel?

Do you have an aftermarket radio?

Rats. A lot of people install aftermarket radios and mistakenly find what appears to be a ground wire in the gray plug. There are no ground wires in either plug, but the tail light wire and the dash light wire will measure very low resistance to ground through all the bulbs on those circuits. Using either of those wires as the ground will put a short on that line leading to blowing fuses. I was hoping you had that problem because it's an easy fix.

What you can do instead of blowing lots of fuses is to plug in a pair of spade terminals, then use a pair of small jumper wires to connect them to a 12 volt light bulb. For this circuit a brake light bulb should work well. When the circuit is powered up and the short is present, the bulb will be full brightness so don't allow it to sit on carpet or against a plastic door panel as it will be hot. Now you can go around and unplug things to see what makes the short go away. When it does, the bulb will go out or dim.