Left rear turn signal fast flashing

[small block ls6]

Hello ..my issues are my left rear turn signal when turned on with all the other lights barely lights up...but all three are barely flashing on left rear...stop light..turn bulb...and backup light...only on left side are on and flashing but barely... when I touch the brake... everything flashes really fast.. except at this point all three lights on passenger side go completely out...my mirror light speeds up and front left turn signal speeds up...but nothing from rear left..and with switch on and no other lights on signal works as usual...but touch brake no brake light on left rear...by the way all fuses are fine..At this point im clueless...bulbs are not burnt ... and one that looked suspect was changed in rear stop bulb...and still same out come...by the way this is on a 2007 GMC YUKON SLT..any info is greatly appreciated

 

[Rocket Man]

Theres a junction block for the rear lighting , it’s under the rear on the right side. It can get corroded from all the road spray going up there. I would inspect that.

 

[petethepug]

Welcome from SoCal. Still running all the OEM incandescent bulbs or are there some led bulbs or aftermarket stuff you may have added?

 

[Doubeleive]

sounds like a short, when the ohm load is not correct the lights can do some really really bizarre stuff

 

[OR VietVet]

Welcome to the forum from Oregon. Yep, junction block.