96 blazer. Noticed today no brk lights. Fuse was blown so replaced and poof instant. Was working ok but not now.
Ideas ???

 

Probably got a wire grounding out causing the fuse to pop. Might have to check and make sure you don’t have any wires frayed and touching metal or other components. It may only pop the fuse when that part of exposed wire touches another wire or another component.

 

Due to age and repeted opening/ closing rear window, wires going to the 3rd light had broken. Severed and shorted out. Repaired and working fine now !!!

 

Thanks for the update. Another potential failure point going into the brain file!