Gauge Lights / Headlights cutting out while driving

A few days ago I thought I noticed my gauge lights flickering while I was driving, but since it was early morning, I just assumed that I was seeing things. Tonight, I was driving in the dark and my gauge lights noticeably turned on and off and then my headlights as well. Anytime I pressed the brake pedal, the headlights would flicker and dim down to extremely low levels. When I went to drive back to my house, I could not replicate the problem. I checked all the fuses and relays, but could not find anything. I did the fog light all the time mod 2 years ago, and pulled my trans to replace my clutch a few months ago. Otherwise, I only have replaced my battery and headlights with silverstars, but I've been running those for over a year or two as well. Any ideas? Can't find any indications of shorts... but I'm sure something could be uncovered with a little digging. 05 xcab v6 6 speed trd offroad