My driver side signal / brake light comes and goes. Bulb is good. I replaced the circuit board 6 months ago and it seemed to fix the problem but it's doing it again. I can take it apart and reassemble it and it'll work for a few days. Maybe the connector? No frayed wiring, nothing visible. Anyone else have this problem?

 

There is a sticky bout the usual breakdowns. Here it is!!
https://www.truckforums.com/forum/chevy-silverado-gmc-sierra-forum-11/common-chevy-gmc-issues-9726/