If the brightness is changing on its own and you are not touching the switch then yes, that is most likely going to be a sun load sensor.
The way this works is the sensor is there to tell the body control module what the ambient light is so that it can adjust the brightness accordingly.
This means we need to start with checking to see if we have a complete circuit on this signal wire to find out if the BCM is getting the proper signal or not.
Basically, depending on the ambient light condition, the voltage is going to vary so we need to use a flashlight while monitoring the voltage and make sure it changes when you shine the light on it.
If it does, then the BCM is likely the issue.
I am attaching the wiring diagram below which will help with determining if there is an issue with this.
Please run through this and let me know what questions you have.
Images (Click to enlarge)
Thursday, May 12th, 2022 AT 8:10 PM