[MrSo0h0o]

resistance= rho(resistivity of mat'l)* length/cross-sectional area

Hence, the longer the wire, the more resistance there is in the wire.
As per Ohm's law, Resistance= Voltage/Current (R=V/I). As a result of greater resistance, we have less current, which causes the light to dim.

 

[MrSo0h0o]

Is it really necessary to have to wire everything from the dome light itself? I found that fuse #25 in the instrument panel fuse box is the fuse for the dome light. Is it possible to run it somehow from the fuse box from the Dome fuse? If so, how would I go about doing it?

I havent tried it out, but I would imagine the dome light fuse would have constant power from the ACC position to the ON position, so it wouldnt go on and off with the dome light. you can try it out if you want though.