Here is one post from tundratalk forum for one of our customer installed our high power switchback LED bulbs on his Toyota Tundra.
I installed the switchback LEDs and the interior lights tonight.
Here is the scoop:
Parking lights on – ignition off:
Ignition on parking lights on or DRLs on:
Lights on:
Then, when you use the turn signals, they turn to amber when the lights are on.
Pretty simple install overall.
While I was at it….I switched out the eight dome and puddle lights….
Before/After: