1993 GMC driver side blinker and brake do not work after replacing bulb and checking fuses
There might be a circuit board back in the tail light housing that goes bad. Check the power in and out of the board. It's called a tail light connector plate under the body exterior section of RockAuto.com - $5-$60 is the price range
Search GMC Sierra 1500 Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
GMC Sierra 1500 Experts