Once the grates and pan have been removed, we can find the sensor at the back of the hood, in the center, screwed into the back of the piece of metal.

Trace the small black wire away from the sensor and up to the logic board so you can see where it connects.

Steps 4 and 5 are alternate methods of disabling the sensor. If you would simply like to move the sensor so it doesn't trigger as early go to step 4. If you would like to disable the sensor so the fan only operates manually go to step 5.