Audio cuts in and out on driver door speaker

[niceguy]

Hi any help would be appreciated

The audio/speaker on my driver door will cut in and out with vibration. When it cuts out it can still be barely heard. When I kick the side panel on the driver side it comes back in

I assume it's the harness but I can't find the physical connector to examine/reseat. Is it under the driver dash or in the door

Thanks