well, it it does it when the brakes are AND arent applied. so the brakes DO have an affect on it. but everything is dim anyway. my temperature gauge sometimes shoots up, and will go back down for no reason as well. sometimes hitting the brake pedal can affect this as well.
about the grounds. i noticed in the engine bay the ground that runs on the right part of the radiator housing thing that goes onto the right of the valvecover is on, but there is 2 parts to it. only one is connected. i see where the other one needs to go, but its not connected. it is one wire, but it splits into 2 that should both connect to the valve cover, i figured if its the same wire, it shouldnt matter. it has been like this since i swapped the engine, and it was fine right after i swapped about 2 years ago, but this just started happening last summer.