Roof Vent Issue: Stuck on Off and Low Speed

edwinklee

Hello: My 2022 T@B 320 roof vent (Dometic Fan-Tastic Vent Fan) three-speed knob is sometimes stuck on Off and 1-Low speed. Sometimes after fiddling it can go to 2-Medium and 3-High. Wonder if anyone knows if there is something wrong with the knob or it is "sensor-controlled" somehow? I cannot figure it out by reading the manual. Any help is appreciated.

Grumpy_G

Sounds like a mechanical failure inside the switch. These switches are dead simple, see this link for pictures: https://www.etrailer.com/Accessories-and-Parts/Fantastic-Vent/FVK1031-05.html 

edwinklee

Thank you for very useful info.

WayneW

Before I replace that switch I would consider the PWM fan mod. It’s cheap ($10?) and results in a variable speed fan that is quieter and uses less energy. I think the 3 factory speeds are High, Too High and Hurricane. 

It’s a pretty easy and cheap mod that I think makes the fan much more useful. It’s also considerably easier and cheaper than replacing the fan w a different model, but that being said, some have switched out fans and love their new one. 

BrianZ

+1 for the PWM fan mod.
Here's photos of how I did mine..
https://tab-rv.vanillacommunity.com/discussion/comment/140981/#Comment_140981
Still working great, and so nicely quiet!