2012 GMC rear blinkers aren't working

Why would it just affect the blinkers? The brake lights and hazards work fine. Could it be the multi switch inside the column that the turn signal lever is attached to?

Are the brake and hazard lights being test in the exact sam manner as the signals?

With headlights on ?

Yes. The brake and hazards work correctly regardless of headlight status.

Can’t edit on this - - site so I’ll just have to add information as it comes to me. Vehicle wired for trailer towing?

Yes, I have a I haul hitch on there but I put that on the day I got it in 2012.

Uhaul

Ok but the thing is those wires are more prone to failures as they are more exposed to the elements.. Combination switch is a possibility - however: Only *hands-on* testing will allow the culprit to be discovered.

Recommend testing commence at trailer wiring.

Just for the heck of it take a look at this: https://www.autogenius.info/gmc-acadia-2011-2012-fuse-box-diagram/ I think you really should use that lmk.

I checked the fuses first with the diagram in the manual.

*TEST* each fuse with signal lights on - using a test light..

Don’t overlook the fuses for towing that is shown in that diagram..

Good luck!