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: