Checking fuses on Tundra for trailer running lights

I'm trying to get my trailer running lights to work and they don't when I plug either of my trailers into both plug ins on the Tundra. (My previous 4runner I had didn't ever have an issue so I feel like it's the Tundra). The contacts for the plug ins look clear and clean too. My fuses all look good including the 30a one for Tow tail. It looks like I may be missing one of the tow tail fuses in the upper left though? Also, how do I know if a relay is bad?

Thanks in advance!

 

Btw, I didn't find out anything out from searching the forum. My brakes, turn signals, and flashers all work just not the running lights on both trailers. I feel like my grounds are all good too since they are on bare metal on the trailer frame. Any help is greatly appreciated!

 

There is a tester that you plug in to the receptacle on your truck to verify that it's working. You might be able to find one locally. Some auto parts stores carry them.

 

Any update? Same issue...