2011 acadia tail light not working when headlights on at night all other lights works

SOURCE: Marker lights, tail lights and dash lights do not work

I had a similar nagging problem once, though I do not recall the dashlights being involved. For me, the lines from the brakes went up the steering column to the turn signal. I pulled the wheel and inspected all the connections, and just like that everything worked again. I believe I could have tugged on the wiring harness without pulling hte wheel and obtained the same results.

SOURCE: Headlights no Taillights

switch burned up due to a short in the tail light wire

SOURCE: no tail lights ,no parking lights, no dash lights

try testing 2 see if u have live running to ur back lightys or change ur light houses

SOURCE: headlights work but dash and tail lights dnt

look for the relay for the parking light

SOURCE: I have a short to ground problem

Try removing the bulbs from the rear tail lights you have one 2 bulb system shorting out, so one at a time remove the bulbs then replace the fuse and see which one is bad or just buy new bulbs and replace, also could be front running light blinker light. But sounds like brake light to ground threw bulb.