88’ Blazer No left Signal or Brake light with headlights

[Charleshugh]

Hey guys, this one’s got me stuck. Recently I’ve had this issue with my left tail light. When the headlights are on: running light works, but my blinker and brake light don’t work and turn off the running light whenever I try to do either. When the headlights are off: everything works great!
The right taillight has no problems with and without headlights.
Anyone have any suggestions or ideas?
Thanks

 

[Barrman]

Check the ground strap inside the light socket for the brake/blinker/running light bulb. Normally the sockets for the front light have the ground strap break.

If that is good, follow the ground wire to make sure it is complete to a good ground.