Dash lights and headlights seem dim

Hello, there's a couple possibilities, low voltage or a bad ground wire to the body control module. This module controls all lights, blinkers etc. The only way to properly diagnose is to check is proper voltage is going in and coming out of the body control module along with voltage dropping the power and ground to the module. And checking. Personally it sounds like a bad ground wire limiting current flow to that circuit causing everything to be low. The headlights are exposed to a pretty hostile environment. For a quick check, go through the fuses to make sure a fuse isn't burned. If you have a test light, go through and check each side of each fuse still plugged in, with key on or engine running. Start there.