I'm kinda confused about what is going on and what you desire to accomplish. If both the dimmer and the dome light are acting funny, that points to the dimmer switch assembly or the wires right behind it.
If you want to fix each without replacing the assembly, the functions have to be treated separately. The cluster lights are one portion (tied into the parking light wire if circumventing the dimmer feature) and the dome light is another issue (being tied into a constant power source).