If it has that option there will be a switch that says rain sensor override or shutoff.
Fantastic fan rain sensor override.
Push and hold the up down button again red light goes out sensor is reenabled.
Below are four photos showing how to disable the rain sensor.
This model comes with a rain sensor that automatically closes the dome when wet.
Here are some generic instructions.
Now all fans are working properly.
If yours doesnt work that way and youre still under warranty have newmar fix it.
Some do and some do not.
Push and hold the up down button for a few seconds red light comes on rain sensor disabled.
Depends upon the model.
The powerful yet compact dometic fan tastic vent model 7350 has automatic variable speeds to get the airflow precisely as you want.