Trouble Shooting Brake Lights - Jeep Wrangler YJ 

I noticed my brake lights were not working while testing my brake lights after the installation of a a trailer hitch harness.
My turn signals and hazard flashers were working - so my lights were not faulty. Your brake lights are the same lights / circuit as your turn signals and hazards. Here are the step by step procedures to track down any bad components or wiring gremlins.