Hazzard and blinker relay Buzz!!

[Free911]

Hey guys.
Got the 74 911 that was sitting for 5 years up and running, everything I needed to get done so far is good. Car runs and drives great. Might need new strut inserts. So,, the 4 prong relay behind the dash that controls the hazard, blinker, and ebrake? has been buzzing. Took it out played with it, broke it and then ordered another. Put the new one in and it is buzzing as well. Buzz stops when the Hazard or the left or right turn signal is on. While it's buzzing the left and right turn lights on the tach flicker a bit, flicker goes away when the buzzing does. I've heard ground is the problem.

Where is the ground for that circuit? I noticed one under dash that has three prongs all with brown wires on them, is that it? or is it something else simple I just don't know.
Ebrake switch is checked and adjusted, light works. Any help would be great. the buzzing is not great.
I would just take it out but its nice having blinkers!