Brake lights on constant. Signals will not override

2022 tundra limited. Trailer brake lights are on constant. My hazards are signals will not work. The boat trailer uses incandescent bulbs if that matters. I figured there might be an LED trailer light controller in the truck? The reason I guess this is because my 2020 Tundra did not have this issue with my boat trailer or my wife's horse trailer and the 2020 tundra did not have led rear lights. Same issue on my wife's old horse trailer. I tried the four pin built in the truck as well as a 4-pin to 7-way and I get the same results. On my wife's horse trailer I use a 6-pin 7 way adapter

 

There’s a trailer light check function in the instrument cluster.

 

The trailer light checklist is grayed out and does not work. I have running lights as well as the constant brake lights on so I don't know why the system is grayed out

 

Update trailer light check is now working as I bought a new adapter. However the adapter also has a trailer light check and it shows the left and right signals still on constant. I can see the trailer light check cycling successfully on the truck but not the trailer

 

You can see the lights cycling on your adapter? That points to your trailer wiring. No turn or brake signal is making it to your trailer. You’re still getting 12V power but hazards/blinker should override the brakes. If you have a multimeter you can check the continuity to ground and continuity to 12V power.

 

No the lights do not cycle on the adapter just on the tailgate of the truck. They are solid on the adapter

 

So then the signal isn’t making it out from your truck. Easiest thing to do is check that the harnesses are all connected. They’re easy to reach from under the truck. Could be a wiring issue too, damaged harness or something. Probably something the dealer needs to fix…

 

I mean the signal is on constantly though so doesn't that mean the signal is making it through?

 

Another update, with my truck completely turned off. the trailer lights and tester are showing a hot connection

 

Here's a picture with the truck turned off and all the lights turned off but still getting constant 12 volts

 

Yeah it’s not supposed to do that. I check the same pins on my truck and it shows zero when off and 0-12 V when turn signal on.

 

I made an appointment to get it looked at the 19th. Should be covered under warranty for them to rewire or whatever they got to do